1- there is 3 backdoor scripts in vBulletin
2- none have any action inside the script
3- none is identifying your mother
A- if you are unlicensed to vbulletin.com, your site may be tracked by their piracy engine to check the validity of your site and if it is proven that your forum is pirated, they send a notice to your host to shut your site down. You also receive a notice to purchase a license OR close the forum. it's not taken in a single minute, they let you choose to become legal or die... they know that 50% of the reported nulled forums will purchase a license because the software is too great to loose, so they let you a moment-- for that, you have to have an original email you are using with your domain registration, because that is where they will contact you *(whois)
B- the backdoor scripts are sending vbulletin.com a checkup code each time it is activated, and if your domain fit with no license, they are alerted. IF you have a nulled version that do not send that checkup, there is no chance vbulletin.com will detect you that way... they have other means.
C- they never sue you, they force your host to close your forum, that's all... i heard about 2 situations where someone was sued by Jelsoft, and they were major cases, not some fan site.
D- i usually check if the GYSN version is safe when they release it... easy, vBulletin backdoor security is the same for 5 years, it's a single line edit in 3 locations. the only bug i have is the install authentication process that GYSN created... completely pointless, but i suppose they wanted to make a stunt...
that's all...
did i mention any legal thing that could make Jelsoft sue me?!.. nope!