It is important to understand that what Twitter has said about their “trends” algorithm makes it very clear that pure volume of tweets is not enough, that they have some anti-spamming tricks in the algorithm, and that they include factors like rate of volume growth and diversity of sources and content. The reason the stupid “fill in the blank” hashtags are “trends” is that they are trend bait: tempting games for random children of all ages in diverse social networks that are the only tags on many unique messages. Gaming the Twitter trends system is something of a challenge because the specific details of the system have never been specified, and a look at the tweetstream of what actually makes it “organically” to the trends doesn’t support the conclusion that  #OccupyWallSt[reet]  ever had trends-type traffic. Instead, #OccupyWallSt[reet] looks more like the tag of an email spammer or 3rd-rate SEO clown: lot of retweets, streams of the same tweet done over and over with just a mention of a media account different in each, the same handful of people retweeting the same things from a tight closed graph, and low-content tweets filled up to the limit from the same cloud of tags. 

Evidence of actual “censorship” would be available to Twitter’s paying customers who have more robust access to the tweetstream and history than they give away for free to their cattle^W users. Given how cheap Google has made it for people to be small-scale advertisers with powerful analytics, I would expect (without having checked) that Twitter also is not charging much for access to their data and tools. It might be possible to know whether there was manipulation of trends for less than the nightly Liberty Plaza pizza budget. Whether anyone cares that much about determining the truth is as yet undetermined, but it seems not, so far.