I had a client send me an ACH that was legitimately a fat finger extra zero. For me, it was a "lot" of truck payments. For them, it was a rounding error that they were unaware of until I reached out and let them know about their mistake. I couldn't wait to make it right with them because it bothered me so much because suddenly I had a pile of money that was theirs and not mine.
I had a similar situation where someone had their email client configured with my address in the reply-to header. We shared a first initial, last name, and isp… also happened to be my email address. His email was firsnamelastname, or something similar. I emailed the guy several times explaining how to fix it, and that I was getting a lot of his business correspondence. Never heard from him.
Then one day I get a Chase Zelle email saying that someone was sending me money. Something like $500. Logged into the Chase app and sure enough, could have taken it with the click of a button.
I contacted the sender to explain the situation and recommended they call the intended recipient for a correct email address.
Couldn’t image just taking it knowing it wasn’t intended for me.