A hashtag is this symbol # - users of Twitter use it to reference a subject that their tweets are on. For example, [url=http://twitter.com/#!/search?q=%23rugbyleaguehere is all the Rugby League talk on Twitter[/url. It's a great way of talking to like-minded people and a very natural way to increase your follower numbers, and less effort than spamming public forums.
The AUP will no doubt have a part that prohibits you from spamming the boards, that's the issue - not how to get your Twitter follower numbers up (although [url=http://twitter.com/#!/GarethMainfeel free to nudge me closer to 2,000 if you like[/url
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