It definitely depends on where you get that data from. You don't have the right to make a copy of an e-book and keep that file on your server/computer for the

It definitely depends on where you get that data from. You don't have the right to make a copy of an e-book and keep that file on your server/computer for the purposes of training AI. Copying that file onto your computer is in many cases already an act of copyright infringement.