People being hacked since the last Server Check.

And why exactly do you believe keyloggers would not show up?

I've been told repeatedly that the "best" keyloggers are personally made and don't appear on virus scans until they're "caught". Second hand information from a person not knowledgeable in this field. I just assumed that if rats could be undetectable, so could these, at least enough of the time to cause some hackings.
If this is not true then please elaborate so I can learn something.