The search works for me, but only when I'm signed out. This leads me to believe that this is some sort of technical issue. Besides, I don't think they are stupid enough to do something like censoring this.
Ahh - wait - I see if you search from the main site, it fails for me now too. http://search.twitter.com works though. Weird. I expect it's due to a some bug/performance failure rather than an intentional censorship. Otherwise search.twitter.com would be censored too.
Regardless of the root cause, I think twitter just took one to the face. This looks pretty bad, even if they come out and say "oh, our spamfilter system malfunctioned."
I sympathise, though. I've run email spamfilters before, and boy, people get /pissed/ when false positives happen.
Headline draws controversial conclusion from incomplete data and should be changed.
For example, this could be the result of automated measures to prevent spamming the trending topics gone haywire. Or not. But accusing censorship without knowing the whole story is just hair-trigger indignation.
I understand that you actually mean well, and mean the question seriously, but in "Internet discussion" the question mark only protects the reputation of the asker, but does nothing to protect the reputation of Twitter.
You're right, of course. But I still think that someone skimming the HN headlines thinks, "Oh, Twitter probably censoring something or it wouldn't be on HN" unless they read the comments.
That's exactly what's so interesting about these kinds of questions. Let's say they were really censoring, and they said, "No, we are not censoring #flotilla," and stopped censoring. You can't tell the difference between that and a bug followed by a bug fix, so they have trouble putting the suspicion to rest.
I note the generally less controversial Stephen Fry is complaining about unrelated Trending Topic oddness this morning, looks like they've screwed up their system somehow and the #flotilla thing is a coincidence. http://twitter.com/stephenfry/status/15064838816
I don't get the technical error message for #flotilla, but a search on the tag acts like it's being ignored. However, http://twitter.com/#search?q=%23freedomflotilla is a trending topic and yields results.
Considering the interests of all involved, this seems to me like the most likely answer. There is no way that people at twitter rationally weighed their self interest and decided to start censoring things. There is zero upside, and a rather large downside for twitter. It's just not in their financial best interest. Israel isn't going to block them or take other action that would financially harm twitter for simply publishing text messages from people. And the publicity fallout from censorship is so obviously bad that there is no way that any rational owner of twitter would approve a move like this.
My money is on a haywire spamfiltering system... but we will see. If the people running twitter are not morons, we'll see an explanation shortly.