I'm usually quite critical of trademark law as I generally think giving exclusive rights to a single company over common English words is wrong. I do, however,

I'm usually quite critical of trademark law as I generally think giving exclusive rights to a single company over common English words is wrong. I do, however, think in this instance Twitter actually have a point - "Tweet" has long been associated with its service, the word itself is a variant of the name "Twitter", and all the early references I can find explicitly refer to Twitter itself.