What should one do who bought stolen devices and used them for many years after his sincere repentance for Allah to accept his repentance?

It is forbidden to deal with a thief regarding the stolen item itself if one is aware of its status, and its sale is invalid. Whoever does so is sinful, because one who takes from a usurper, a thief, or an aggressor is like them, as long as he knows that they have transgressed the rights of others.

If the stolen item is present in its original form, it must be returned to its owners. If anything is missing from it, its value must be guaranteed. If it has been consumed, it must be guaranteed by an equivalent if it is a fungible item, or by its value if it is a non-fungible item.

Whoever has taken something from a thief must repent and return it to its owners if he knows them; otherwise, he should give it as charity on their behalf. It is permissible to claim back the price paid to the thief.