This brother is to be commended for his protective jealousy regarding haraam things and for his hatred of sin and desire to combat it and rid the people of its evils. But we do not advise him to look for bad sites in order to tell the centre to block them. That is for many reasons, including the following: 

1 – the Prophet (peace and blessings of Allaah be upon him) has informed us of and warned us against the temptation (fitnah) of women. Undoubtedly the fitnah of naked women in different poses is very great. 

It was narrated that Usaamah ibn Zayd (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “I have not left behind me any fitnah that is more harmful to men than women.” Narrated by al-Bukhaari, 4808; Muslim, 2740. 

2 – The Muslim is commanded to keep away from places of fitnah and to flee from places where it is present and shun its people. Undoubtedly seeking out these sites goes against all of that. 

It was narrated that ‘Imraan ibn Husayn (may Allaah be pleased with him) said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Whoever hears of the Dajjaal, let him flee from him, for by Allaah, a man may come to him thinking that he is a believer, then follow him because of the specious arguments that he presents.” Narrated by Abu Dawood, 4319; classed as saheeh by al-Albaani in Saheeh al-Jaami’, 6301. 

Ibn al-Jawzi (may Allaah have mercy on him) said: 

Beware – may Allaah have mercy on you – of exposing yourself to the causes of calamity, for it is unlikely that those who approach fitnah will be safe from it. Just as caution leads to being safe, so too exposing oneself to fitnah leads to doom, and it is rare that one remains safe from fitnah when approaching it; even those who are safe from fitnah when they approach it will not be safe from thinking about it or being influenced by it. 

Dhamm al-Hawa, p. 126 

3– The Muslim is commanded to lower his gaze and avoid looking at haraam things; checking on these permissive websites and what is in them goes against this command. 

Allaah says (interpretation of the meaning): 

“Tell the believing men to lower their gaze (from looking at forbidden things), and protect their private parts (from illegal sexual acts). That is purer for them. Verily, Allaah is All‑Aware of what they do”

[al-Noor 24:30]

Ibn Katheer (may Allaah have mercy on him) said: 

This is a command from Allaah to His believing slaves to lower their gaze and avoid looking at that which is forbidden to them, so they should not look at anything except that which Allaah has permitted them to look at. If their gaze happens to fall upon something haraam, then it is unanimously agreed (among the scholars) that if a person’s gaze falls upon something haraam unintentionally, then he should look away immediately. It was narrated by Muslim in his Saheeh that Jareer ibn ‘Abd-Allaah al-Bajali (may Allaah be pleased with him) said: I asked the Prophet (peace and blessings of Allaah be upon him) about an accidental glance, and he told me to look away. 

Tafseer Ibn Katheer, 3/282 

4 -  The saheeh text states that it is forbidden for a man to look at the ‘awrah of another man, so what about a man looking at the ‘awrah of a woman? 

It was narrated from Abu Sa’eed al-Khudri that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “No man should look at the ‘awrah of another man, and no woman should look at the ‘awrah of another woman.” 

Narrated by Muslim, 338. 

5 – The Muslim is forgiven the first glance, but repeatedly looking at corrupt sites goes against that. 

It was narrated that Buraydah ibn al-Husayb said: The Messenger of Allaah (peace and blessings of Allaah be upon him) said to ‘Ali: “O ‘Ali, do not follow one glance with another; you are forgiven the first but not the second.” Narrated by al-Tirmidhi, 2777; Abu Dawood, 2149. classed as hasan by Shaykh al-Albaani in Saheeh al-Targheeb, 1903. 

It was narrated that Jareer ibn ‘Abd-Allaah said: I asked the Messenger of Allaah (peace and blessings of Allaah be upon him) about an accidental glance, and he told me to look away. Narrated by Muslim, 2159. 

Al-Nawawi said: 

What is meant by an accidental glace is if one's gaze falls upon a non-mahram woman accidentally; there is no sin in that initially, but he must look away immediately. If he looks away immediately, there is no sin on him, but if he persists in looking, then he has sinned, because of this hadeeth, for the Prophet (peace and blessings of Allaah be upon him) commanded him to look away. And Allaah says (interpretation of the meaning): 

“Tell the believing men to lower their gaze (from looking at forbidden things), and protect their private parts (from illegal sexual acts)…”

[al-Noor 24:30]
Men must lower their gaze and avoid looking at women at all times, except for sound and legitimate purposes, namely testimony, medical treatment, proposing marriage, buying a slave girl, buying and selling, etc. In these cases it is permitted to look only as much as is necessary and no more. And Allaah knows best. 

Sharh Muslim, 14/139 

6 – The Prophet (peace and blessings of Allaah be upon him) called a forbidden glance the “adultery of the eye”. In addition to it being haraam in the sense of transgressing the limits with regard to looking, it is also an act of ingratitude for the gift of sight that Allaah has bestowed upon the Muslim. 

It was narrated from Abu Hurayrah that the Prophet (peace and blessings of Allaah be upon him) said: “Allaah has decreed for the son of Adam his share of zina (adultery), which will inevitably happen. The zina of the eyes is looking, the zina of the tongue is speaking; the heart hopes and wishes for that and the private parts confirm it or deny it.” Narrated by al-Bukhaari, 5899; Muslim, 2657. 

Al-Nawawi said: 

What this hadeeth means is that a share of zina is decreed for the son of Adam; in some cases zina will be in a real sense, namely unlawful sexual relations; in other cases it will be zina in a metaphorical sense, by looking at haraam things, or listening to stories of zina and things that have to do with it, or by touching a non-mahram woman with his hand or kissing her, or by walking to zina, or looking, or touching, or speaking in haraam ways with a non-mahram woman, and so on, or by thinking of it in one’s heart. All these are metaphorical kinds of zina. 

“The private parts confirm that or deny it” means, zina with the private parts may or may not take place even though a person may have been approaching that. And Allaah knows best. 

Sharh Muslim, 16/206 

7 – There are an estimated 8 billion permissive websites, up from approximately half a billion in 1998. So how about now? If you were to give each website a quick glance, how would your heart end up? How much time would you waste in seeking them out? Undoubtedly doing that would destroy one's heart and body, and would be a waste of time. 

8 – Continually looking at these evil and provocative sites may cause one to become attached to them, so his heart would be filled with forbidden love and become corrupted. Thus he will have exposed himself to fitnah and doom after having been sound and healthy. 

Ibn al-Jawzi (may Allaah have mercy on him) said: 

A person may be exposed to the causes of love so he falls in love, and he may see a person and this first glance does not create love, but repeatedly looking at that person and mixing with him or her may lead to what was unthinkable. Some people may look at a person and that creates some kind of love, but then they keep away and the love disappears, because continual looking may cause love to grow, like a garden planted with seeds which, if it is neglected, will shrivel and die, but if it is watered it will flourish. 

Dhamm al-Hawa, p. 237 

Ibn al-Qayyim (may Allaah have mercy on him) said: 

The more looks follow one another, the more the heart becomes attached, like water with which a tree is irrigated. If too much water is given the tree is damaged. Similarly if glances are repeated that undoubtedly corrupts the heart. If the heart is exposed to this problem, it will turn away from what it has been commanded and the person will be faced with problems which will inevitably lead him to commit forbidden actions, and his heart will be destroyed. The reason for that is that the one who looks enjoys looking the first time, then he wants to look again, like eating delicious food, when he takes the first bite. But if he had lowered his gaze from the outset, his heart would be at peace. 

Rawdat al-Muhibbeen, p. 94, 95 

And he said: 

Letting one's gaze wander leads to becoming heedless about Allaah and the Hereafter, and will make him intoxicated with love, as Allaah says concerning the lovers of images (interpretation of the meaning): 

“Verily, by your life (O Muhammad), in their wild intoxication, they were wandering blindly”

[al-Hijr 15:72]

Looking is like a glass of wine, and love is the intoxication that results from that. The drunkenness of love is worse than the drunkenness caused by wine, for the drunkenness caused by wine will pass, but the drunkenness of love rarely passes until one is in the throes of death. 

Rawdat al-Muhibbeen, p. 104 

9 – Repeatedly looking at those evil sites may lead a person to commit haraam actions, or to imitate the things he sees. So it starts with looking, and ends with committing haraam deeds. 

Ibn al-Qayyim said: 

Looking is the origin of most of the problems that befall man, because looking generates thoughts, then thoughts generate ideas, and ideas generate desires, and desires generate will, which then becomes stronger and becomes firm resolve, in which case the deed will inevitably be done unless there is something to prevent it. Hence it was said that patience in lowering the gaze is easier than patience in bearing the pain that comes afterwards. 

Al-Jawaab al-Kaafi, p. 106 

10 – Repeatedly looking at those evil sites causes other kinds of harm too, such as desensitization, and after a while you will never regard that thing as evil and you will get used to looking. This is a sign that the heart has died and lost the shar’i sensitivity towards sin. Another effect is that you expose yourself to suspicion, if someone sees you going to these sites or if others see that on your computer.  

Finally, 

What you should keep away from is looking at these sites, even if the purpose is to inform the authorities of them, for the Shayatan may make you go to these sites on this basis and then lead you to worse sins after that. 

There are technical means available which mean that the Muslims does not need to seek out these sites, and there are specialized committees in some government departments and companies who block these sites. Undoubtedly when a committee in a work place views such things, that is not like a person viewing these sites alone at home, because the person who is doing that alone is more likely to fall into the trap of these sites.  

We are not speaking of something imaginary or something that is impossible or unlikely. We often hear stories of righteous young men who have been tempted by these sites; they start with a glance, then they waste their time with them. 

You have no need of all that; protect your capital and do not take risks. We ask Allaah to write your reward in full and to make you steadfast in adhering to truth and guidance. 

And Allaah knows best.