You're choosing to disbelieve people because you don't like them. You would have believed them if you liked them and they said the same thing, because if you've spent any time at all online you know it happens.

That's not the same as disbelieving an anonymous spammer. Your distrust of them does not stem from disliking them.

To me, your attitude seems like indifference to the truth: I think you know that this happens, and it would be VERY odd if it only happened to people you like, but you're just indifferent when it happens to people you don't like, so you disbelieve them out of spite.