Praise be to Allah.
If it is possible to control what happens in the internet café and prevent evil, there is nothing wrong with opening it and the income that results from that is halaal. But if it is not possible to control it and the customers use it for things that Allaah has forbidden, such as looking at haraam things and doing evil things – as is the case with most such cafes and their customers – then it is not permissible to open it and the income that results from it is haraam. In that case you have to change the place to another project in which there is no sin and you can earn a halaal income from it, which will help you to worship Allaah by going for Hajj, getting married, etc.
See also the answer to question no. 34672
The Standing Committee for Issuing Fatwas was asked a detailed question about internet cafes, which we will quote here:
Question: There is a lot of talk nowadays about Internet cafes which have become widespread recently. What is the ruling on investing and dealing in these cafes? Knowing that there are some harmful and haraam things, as follows:
1 – The user rents a computer by the hour, although we do not know what the user is going to use the internet for. There are many programs and sites which the user can access, some of which are beneficial and some are harmful. There are some sites which the King ‘Abd al-‘Azeez Science and Technology City can control and block, but there are some users who are able to enter the forbidden sites anyway.
Please note that we cannot control the programs except by cancelling the service.
2 – There is a program called Microsoft Chat, which is for chatting and corresponding, through which users can exchange bad language and foul talk, and they can send and receive pornographic pictures and movies. It is possible to control the sending and receiving of pictures and movies, but there are some people who can break these controls in devious ways.
Answer: If this equipment can be used for false and evil ends, which will harm Islamic beliefs or enable people to look at permissive pictures and movies, or news of immoral entertainment, or to have dubious conversations and play haraam games, and the owner of the café cannot prevent these evils or control the machines, then in that case it is haraam for him to deal in that, because this is helping in sin and haraam things, and Allaah, may He be glorified and exalted, says in His holy Book (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 Allaah is the Source of strength. End quote from Fataawa al-Lajnah al-Daa’imah (26/284)
And Allaah knows best.