Just comes to show how careless people are in general. It only takes like what? less than 5 seconds to double check the address you're sending the funds to?
There's more to it than that: when I receive a PM with a payment address, I first have to make absolutely sure it came from the real account. With email, most people don't use encryption. That makes it even more difficult to be absolutely sure the sender is who he says he is.
..aaaaand not only that! Personally, even though I'm already certain that the bitcoin address came from the legitimate person, I always ask the person to verify the pasted address! Like so:
Tradee: my address is bc1jf5jxxxxxxxxxxxx
Me: bc1jf5jxxxxxxxxxxxx
Me: ?
Tradee: bc1jf5jxxxxxxxxxxxx
And I even do that even with transactions as low as $20. You can never be so sure.