Quoting Bruce Perens (bruce@???):

> It doesn't, unless you have understanding customers who just don't
> redistribute because they want you to stay in business. But grsecurity
> doesn't work that way, it is alleged. It is alleged that they tell
> customers that if they redistribute, they will no longer be allowed to
> be a customer or get the next version.
>
> IMO that's violating the GPL.

IMO, terminating a customer relationship and contractual entitlement to
future releases is nothing like a 'restriction on the recipients'
exercise of the rights granted herein' within the meaning of GPLv2
clause 6, because zero impediment is thereby imposed on licensee's
lawful exercise of licence rights. Commercial support and updates are
nowhere guaranteed by the licence terms.

You obviously disagree. Judges would get to decide, provided the claim
were ever adjudicated, but I think that outcome's wildly improbable
because plaintiffs aren't dumb enough to bring such cases.