This is not a site which is a target for hackers, we're too small, we're under the radar.
We have never had any issues because we've not been up to the latest version of vBulliten.
Obviously I get the point of upgrades but every time we've done an upgrade (admittedly only a couple of times) it has caused issues which have pissed people off and it's been more trouble than it's worth. It may just be co-incidence this time though as the problem didn't initially show itself.