“Islamic” T-shirts

It is not permissible to buy or wear these T-shirts, and the one who wears them should be denounced, because they involve disrespect towards the name of Allah, which is bound to be mistreated by being printed on these shirts, whether they are thrown in places where Allah’s name should not be put, such as in bathrooms (especially when they get dirty and need washing) or are mistreated in other ways. If you and other Muslims refrain from buying these shirts, this will narrow the market for them, which will force the producers – if their aim is merely commercial – to stop printing them. And Allah knows best.