Is it permissible to rent out a shop for the purpose of opening an internet and networking café, and is the landlord obligated to investigate the details of the tenant's business?

The contract of Ijarah (leasing/hiring) is permissible in Islamic law, but it is not valid if the benefit derived from it is forbidden, such as leasing a shop to sell alcohol. Accordingly, leasing an internet cafe is permissible if the lessee commits to regulating it and preventing forbidden acts within it. Otherwise, it is not permissible to lease it due to the cooperation in sin and transgression involved.