Unsettling Speculation

It's been known for a while that some terms listed as interests on LiveJournal cannot be searched for using LiveJournal's own search system. Tonight the LiveJournal folks posted a bit about that, but frustratingly didn't really say anything other than admit that the blocking existed and that the blocking system would be tweaked to be more specific and less likely to block untargeted terms. Naturally, they were called on this and asked what the reason for the blocking was. The responses have been "We can't say." or "We can't answer those questions right now."

I haven't heard of this happening with any other journaling site, and I suspect if it did that news that such blocking was happening at multiple sites would spread rapidly. It'd likely hit Slashdot and Fark pretty fast. So, as that has not happened, it seems to be LiveJournal specific. If it was simply LJ policy, they could talk about - they might not want to, but they could. So, suppose they're actually being truthful when they say they can't give details. What could explain that?

The only thing I can come up with, and I admit this pure speculation on my part, is some sort of settlement (threatened lawsuit based on "hate speech" perhaps?) that had provisions that LiveJournal would have to block some terms, and that LiveJournal could not reveal the instigators of the blocking.

Assuming there is a genuine reason for the blocking, and that LiveJournal truly cannot talk about it, is there any other explanation?