The fast-spreading exploits proved two things: Twitter is undoubtedly now a mainstream service, and it's joined the ranks of big-time tech companies as a target for hackers. Security experts interviewed by CNET say the messaging service has done a fair job of protecting itself so far, but will have to be more careful with its coding if it wants to be trusted for news aggregation, integration on corporate sites, and as a useful international communication tool. "They're just as much in the crosshairs as Microsoft, Adobe, and Facebook," said Beth Jones, a senior threat researcher at Sophos. Twitter doesn't necessarily have more holes than other sites, but the ones it has seem to be targeted at a high frequency by hackers interested in experimenting with new attacks and testing how far and fast dubious software can spread over the popular social network. Is Twitter the New Playground for Hackers? Twitter became a target for hackers this morning as a fast spreading worm used a ‘mouseover’ hack to annoy many of its users.