Can you go to jail for giving someone a lost phone?
The best thing to do would be to get the phone back, look at the
contacts, and try to return the phone to the rightful owner. I
found a phone once and looked through the contacts and found "Mom".
I called the number from their phone and told her that her daughter
had lost her phone. I then was able to get the phone back to the
owner. You probably won't go to jail because it would be hard to
track you down, but you're the one who has to live with the guilty
conscience. Do the right thing. You will be rewarded someday for
your honesty.