I think it's hard to believe in someone in this unbelievable world.
If you do not trust anyone in this world, then no one will trust you either. you will get what you give to other people. just stop cheating others and then no one will not cheat you. This is a very simple law that works. Watch out for yourself.
In Internet I would , too , advised would no one not trust, all try to cash in on you, only if and trust the only those people which you know in real life!