Well, I've done some digging around to try to help out their situation.
It seems there might have been several breaches of contract, and possibly tortious interference of contract on top of it. After several readings of vBulletin's license, plus a couple of confirmation e-mails directly from vBulletin staff, I have pretty solid backing for my belief.
But, first, a quick TL;DR analysis:
The license owned by Carenath means any data created for FAF belongs to him from the time period his license became active. Now, the forum license BEFORE, Dragoneer's claimed registered vBulletin v3, already had the role of FA forums, and thus any data belonging to that time frame up to the activation and usage of Carenath's license is rightfully FA/IMVU's.
Now, here comes the quirky part, if I am understanding everything correctly. Disclaimer, I am quite on Carenath's side, but he's not blame-free, either, and I am going to point out fuckups.
vBull's licensing Section 1.4 and emails state "One Domain, One License. Transferable after 90 days of use, $45 transfer fee, one transfer only." The domain was moved to a different license - not allowed without paying an appropriate transfer fee. Dragoneer and Carenath both fucked up here, with 'Neer likely doubly-so in selling over to IMVU without written vBull permission and paying the fee, knowing his typical incompetence.
vBull's licensing does not allow the transfer of data from the database, nor the selling of information from the database for profit - Carenath and 'Neer again are both at fault for this. The forums should have been separated out, and users that would've liked their posts from the old forums to be on the new forums should have been allowed to copy/paste, from the get-go. Since this was not an officially-sanctioned vBull upgrade path, this was the only allowable course of action.
Now, sections 1.1 and 1.8 of vBulletin's software license agreement make it very clear that the data is owned by the LICENSE OWNER (with 1.8 covering data/database as derivative works and related materials,) and is not to be transferred without sanctioned approval of vBull. For IMVU to take more data than they were legally allowed is a tortious interference of contract on Carenath and vBull's end. I'm rather sure there's no audit trail of that, either.
I really want to point out "1.3 Illegal Activity. You may not use the Software to engage in or allow others to engage in any illegal activity where the Software is accessed and/or used. You may not use the Software to engage in any activity that will violate the rights of third parties, including, without limitation, through the use, public display, public performance, reproduction, distribution, or modification of communications or materials that infringe copyrights, trademarks, publicity rights, privacy rights, other proprietary rights, or rights against defamation of third parties."
*CoughFirePyro/Furpimpersonationcoughburp*
Let us note section 12 - Governing Law. "The License and this Agreement are governed by and construed in accordance with the laws of the State of California, United States of America. You hereby consent to the exclusive jurisdiction and venue in the state and federal courts of the County of Los Angeles, California and the Central District of California, respectively."
I know what just happened won't fly in a California court, I live here and I whipped EA's ass here. vBull and IMVU are both HQd here, this court will most certainly have jurisdiction and will hold IMVU/FA/'Neer liable for the breach and interference of vBull's contract with Carenath. California has some STRICT data protection laws and will uphold vBull's ToS which is providing those protections.
But, on the same hand, the court would also likely find against Carenath for those fuck-ups I mentioned. Thankfully, the fee is only $100 per fuckup, per the ToS. IMVU/FA would have bigger problems to face re: that user data gathered against the vBull/Carenath contract. They can claim huge damages in tortious interference of contract between themselves and Carenath, and multiple breaches of the contract are quite apparent.
And I'd be more than willing to bet that IMVU would (given their propensity to plaster porn ads all over the place) put the same ads on the forums, yet violating another T&C in the ToS - no malware distribution through that platform.
This whole cockup makes me smile yet shed a tear at the same time, as the blame runs rather square on both sides, with a bit more falling towards IMVU/FA/Neer being the primary fault.