Praise be to Allah.
Undoubtedly the burden of sin rests primarily on the one who commits the haraam action, whether that is looking, writing or speaking, but a share of it also rests on the one who helps him to do that and makes it easy for him, and also on the one who sees an evil action but does not denounce it. In the answer to question no. 34672 we have stated the ruling on working in an internet café:
It is not permissible to work or invest in internet cafes unless they are free of evils. That includes not allowing patrons to enter haraam sites, by blocking them or by throwing those patrons out if they persist in using them. That is because Allaah says (interpretation of the meaning):
“Help you one another in Al‑Birr and At‑Taqwa (virtue, righteousness and piety); but do not help one another in sin and transgression. And fear Allaah. Verily, Allaah is Severe in punishment”
And the Prophet (peace and blessings of Allaah be upon him) said: “Whoever among you sees an evil action, let him change it with his hand (by taking action); if he cannot, then with his tongue (by speaking out); and if he cannot then with his heart (by hating it and feeling that it is wrong), but that is the weakest of faith.” Narrated by Muslim, 49.
Shaykh Ibn Baaz (may Allaah have mercy on him) said: Denouncing it in one’s heart is obligatory for everyone. That means hating the evil action and shunning those who do it, if one is unable to denounce it by taking action or speaking out.” From: al-Durar al-Saniyah fi al-Ajwabah al-Najdiyyah, 16/142.
If it not possible to regulate what happens in this café and prevent evil things, it is not permissible to open such a café, as a precaution against falling into sin and disobedience.
If you cannot denounce evil in this café then you should save yourself and shun those who commit sin. There is no guarantee that the wrath and anger of Allaah will not befall them. Look for permissible work from which you can acquire permissible wealth. We remind you that Allaah says (interpretation of the meaning):
“And it has already been revealed to you in the Book (this Qur’aan) that when you hear the Verses of Allaah being denied and mocked at, then sit not with them, until they engage in a talk other than that; (but if you stayed with them) certainly in that case you would be like them”
Al-Qurtubi (may Allaah have mercy on him) said in his Tafseer: The words “then sit not with them, until they engage in a talk other than that” mean: words other than kufr. “(But if you stayed with them) certainly in that case you would be like them” – this indicates that it is essential to avoid sinful people if they commit some evil action, because whoever does not avoid them is in effect approving of their actions, and approval of kufr is itself kufr. Allaah says, “you would be like them”, so whoever sits in a gathering of sin and does not denounce them bears a burden of sin just like theirs.
They should be denounced if they speak of sin or commit sin. If a person is not able to denounce them then he should get up and leave so that he will not be one of those mentioned in this verse.
It was narrated from ‘Umar ibn ‘Abd al-‘Azeez that he punished some people for drinking alcohol, and it was said to him concerning one of those who were present that he was fasting. So he punished that man more severely and recited this verse: “you would be like them” – i.e., approving of sin is in itself a sin. Hence the one who does the action and the one who approves of it are both to be subjected to the punishment for that sin, so they are all doomed. (5/418).
Moreover there is the fear that if a person works in these places his faith will become weak and the sense of protective jealousy (gheerah) will vanish from his heart. The Shaytaan may even entice him to commit sin. Allaah says (interpretation of the meaning):
“O you who believe! Follow not the footsteps of Shaytaan (Satan). And whosoever follows the footsteps of Shaytaan (Satan), then, verily, he commands Al‑Fahsha’ [i.e. to commit indecency (illegal sexual intercourse)], and Al‑Munkar [disbelief and polytheism (i.e. to do evil and wicked deeds; and to speak or to do what is forbidden in Islam)]”
It should be noted that whoever gives up something for the sake of Allaah, Allaah will compensate him with something better than it, and that what is with Allaah can only be attained by obeying Him. Allaah says (interpretation of the meaning):
“And whosoever fears Allaah and keeps his duty to Him, He will make a way for him to get out (from every difficulty).
3. And He will provide him from (sources) he never could imagine. And whosoever puts his trust in Allaah, then He will suffice him. Verily, Allaah will accomplish his purpose. Indeed Allaah has set a measure for all things”
We ask Allaah to provide you with permissible, good work and to bless it for you. And Allaah knows best.