Greetings, I have a 24" Aluminum IMAC Leopard 10.5.8 and recently responded to a known hacker on Facebook, which is all this guy neefds to hack into a computer. Firstly, is there anyway to prove or disprove the concern about being hacked. If I am hacked -- what can I do? Apple tech support told me that if everything is turned off in "sharing" in system preferences than I am okay and have no reason for concern. Any ideas? Thank you.