Some of the forums I read are suggesting the use of virus laden Email attachments, which gives rise to the astonishing possibility of the law enforcement agencies lowering themselves to the same level as the "hackers".
The most common advice is
1) A good firewalled router
2) A personal firewall in each P.C.
3) Frequent scans with up to date Anti Virus & Anti Spyware utilities ( but you already do that, don't you......)
4) Don't use WiFi unless you have to. In which case enable WPA, rather than WEP encryption, and use MAC code addressing to further restrict the possibility of unauthorised access.
5) As there have even been suggestions of physical breaking & entering!!, make sure the computers are password protected and keep the keyboard somewhere safe, away from the machine when not in use.
This may well sound like paranoia, but the way things are going, better safe than sorry....