An Aussie teen has fessed up to sending thousands of Twitter users to Japanese porn sites.

The 17 year old Pearce Delphin said admitted exposing a security flaw which was then pounced upon by hackers, affecting thousands of users and causing havoc on the microblogging site for about five hours. Delphin, who lives with his mum and dad in Melbourne, said he tweeted a piece of "mouseover" JavaScript code which brings up a pop-up window when the user hovers their cursor over the message.

The idea was taken up by hackers who tweaked the code to redirect users to pornographic sites. Delphin said he did it to see if JavaScript really could be executed within a tweet.

He told AFP that at the time of posting the tweet, he had no idea it was going to take off how it did. The teen still has not yet told his parents about it all and clearly they don't read the papers.