"if you run a decent anti-virus program and keep it updated, you have nothing to fear from that"
no one anti-virus can spot everything, and some trojans effectively disable some scanners. add to that the fact that new trojans are written all the time, and it takes time for them to be reported/figured out, and i'd hardly say there is "nothing" to fear.
judging by the number of port scanning attempts i see every day, i should win the lottery any time now
