Yeah, I don't believe it unless you send actual proof.
Most likely, you're just expecting people to PM you so you can scam them in one way or another.
That aside, Steem accounts work in a similar way and I have actually received some Steem by accident in the early days.
The founder of Steem's account is @dan and my Steem account is @daan, someone sent me around $200 in Steem very early on because of this mistake