I really wanted to avoid giving any sort of reasoned opinion in this thread, but, it seems there's so much FUD that it really can't do any harm.
And............... We all know this how? Where exactly did you get your law degree again?
I know you asked this of someone else, but, let me answer - I got mine in Scotland, UK. Although Scotland (and N. Ireland) have separate legal systems to England and Wales, the law on this kind of stuff is more or less the same across the whole of the UK (with some technical differences).
One of the key cases on "breach of confidence", which covers situations similar to what Internet Brands seem to be claiming, is "Faccenda Chicken v Fowler [1986] 1 All ER 617" (it's actually an English case, so it's all good for this situation).
One of the key passages that this turns on:
"Secondly, there is information which the servant must treat as confidential (either because he is expressly told it is confidential, or because from its character it obviously is so) but which once learned necessarily remains in the servant's head and becomes part of his own skill and knowledge applied in the course of his master's business. So long as the employment continues, he cannot otherwise use or disclose such information without infidelity and therefore breach of contract. But when he is no longer in the same service, the law allows him to use his full skill and knowledge for his own benefit in competition with his former master; and ... there seems to be no established distinction between the use of such information where its possessor trades as a principal, and where he enters the employment of a new master, even though the latter case involves disclosure and not mere personal use of the information. If an employer wants to protect information of this kind, he can do so by an express stipulation restraining the servant from competing with him (within reasonable limits of time and space) after the termination of his employment."
That's actually what a real judge has decided in the UK, which was appealed and upheld. Lots of UK case law is now available freely online, it's there for anyone to go and see.
On the assumption that Kier, Mike and Ashley wouldn't be stupid enough to copy vBulletin code directly (which is all Copyright law in the UK protects in terms of software - other issues are dealt with separately) then based on the previous case law on this, my opinion based on my Scots law degree (and to note, I'm not a lawyer) is that assuming Kier, Mike and Ashley followed the terms of their non-competes and other relevant employment clauses, that XenForo should legally be in a strong position. Obviously there are other issues about whether they'll have the cash to fight etc... etc... but that's not really something being right OR wrong is going to change. Sure, it involves some assumptions - but I really can't see Kier, Mike and Ashley doing anything else. Given IB likely haven't seen the code, most of their claim must be based on them taking over knowledge from having worked on vBulletin and applying it to XenForo (which an English court said was more or less OK, see passage above).
Everyone is entitled to throw around opinions and speculation (obviously within the rules set down by IB/vB) but others attacking others just because they think they know better, and often spouting law or legal positions that don't relate to the UK, is becoming quite annoying and grating.
