for others that still ask this question,
from my point of view...and many others
if your using a keygen, ONLY if Jelsoft send a complaint or a user sends to jelsoft they may act towards it as who are your server owners or support team to know if that license is ures or not unless they backup & at the time of the backup the Keygen was left on your site....so Keygen must be deleted straight after installation, & Jelsoft finding out from a complaint from someone takes time and normally don't act as people change their site alot and forget to update there detail at jelsoft, so they'll check with them before anything which really is a long process when you get many complaints over there and they'd go for the nulled with no keygen script before this (that does'nt mean its impossible)... unless the complaint is from the license owner...Then your F###'d...LOL
I've been using nulled vb for 2 and 1/2 years with the same hosting company but all with keygens & not nulled and nothing has happened so far although the company IS very stricked and I've seen alot get their account suspended ...fingers crossed for the time to come, lol
if your not using a keygen there's a bigger possibility, jelesoft complaining which will be straight away if they find you "in the middle of thousands of others " which would be unfortunate as there will be no license.....
and/or 1 of your server support team or admins know about vb and its licensing and know's about nulled vbulletin scripts......but using a keygen gives you a license number.
over all it is very rare if you get caught whlie using a keygen if your site contains legal content but it does'nt mean its NOT POSSIBLE CAUSE IT IS!!