Twitter has sent out out a stark warning to its users: Stop the spam or else!

The microblogging site has just settled a lawsuit against one of the biggest perceived spammers on the site, an automated marketing tool known as TweetAdder, which effectively blocks the service from being able to access Twitter ever again.

The move is just the latest in a series of actions by Twitter against spammy accounts and the kinds of services that enable them to do it. All things D reports that the site has gone after a number of services which its says helps users to abuse its terms and conditions through the automation of certain functions. TweetAdder, together with services like TweetBuddy, TweetAttacks, Justinlover and Troption, all serve to allow marketers and entrepreneurs to spam other users. As a result, Twitter has taken legal action against all of them, and has already come to an agreement with TweetBuddy, which has now closed down its operations.

TweetAdder is probably the best known Twitter spam service around, one that bills itself as the “Ferrari of Twitter marketing software”. Among its functions, it allows twitterers to target users based on their interests, and can automate numerous functions like direct messaging, retweeting, following and unfollowing. It also allows spammers to target users that mention specific hashtags or keywords.

Now though, it looks as if TweetAdder is finished. The settlement, which was announced yesterday, effectively bars TweetAdder from sending any more “unsolicited commercial messages”. In addition, it’s no longer allowed to claim that using its services will prevent a user’s account from being locked.

As an occasional Twitter user I’m not really that concerned by the spam, mainly because I’ve never been exposed to that much. However I know that many people have been targeted, and these will no doubt be pleased that Twitter is trying to do something to stop it. Indeed, it’s fair to say that Twitter has been more proactive than most sites when it comes to clamping down on spammers. Last year, it finally began blocking users found to be guilty of excessive use of automated software, while the rules and regulations governing its use are some of the strictest I’ve seen.

Nevertheless, having these rules in place is one thing, but enforcing them will be quite another – it’ll be a miracle if Twitter really does achieve its aim of becoming totally spam-free.