Did Twitter censor the #flotilla hashtag following the Israel attack?

The attack by Israel on a flotilla of ships approaching Gaza has, as you'd expect, generated a huge response on social media - and of course Twitter, with its real-time content, was quick to react.

Many users began the morning by tagging their comments about it with "#flotilla" - a "hashtag" which gives a structure to a discussion or emerging event, as you can filter searches in applications such as Tweetdeck so that you only see those with that tag.

But at around 11am, as #flotilla began "trending" - rising to the topmost-used hashtags on the service - it seemed to vanish.

Was this censorship by Twitter? Quite a few asked the question.