Perhaps the greatest thrill for any prankster is to have his hoax taken as truth. Just such a thing has happened to Ray Owens, who runs a website called Joke A Day.

Owens sent an email to his 342,000 subscribers on 5 June warning them of a new virus called AOL.exe. Warning people of a virus seems like a nice thing to do. But AOL.exe isn't a virus at all, it's the AOL application that provides internet access to millions of people worldwide.

Owens’ prank is a riff on the sulfnbk.exe virus hoax circulated at the end of May which warned users to delete the file sulfnbk.exe. The file is not a virus at all, but a necessary Windows file.

Owens chose AOL.exe because "the absolute stupidest people [who write him letters] all proudly carry The overwhelming majority of AOL people do not read instructions. They do not follow directions. They do not have any business near a computer whatsoever," he wrote.

Subscribers were warned of a virus called AOL.exe that would activate on 8 June. The prank email then instructed them how to remove the offending file from their computers.

The warning starts out innocently enough, saying that ‘deleting this file will fix a damaged 30 megabyte [sic] area of your hard drive and restore it to full functionality’.

However, victims of the hoax perhaps deserve less sympathy if they deleted the file even after being told: ‘Keeping this file on the system after 8 June will cost you $2.90 more per month!’ This is a reference to the fact that AOL is raising its monthly rates in July by $1.95 a month.

‘Failure to remove this file will keep your 'upper memory management' module of your intelligence quotient blocked,’ continued the email. ‘Deleting AOL.exe will free your IQ to go above 85!!! Deleting this file will allow you to spell correctly and use the English language properly.’

AOL says the hoax has resulted in only a "negligible number of calls", according to company spokesman Nicholas Graham. Still, it means some people really were foolish enough to fall for it.