Spammers are being thwarted by finding that their junk messages unexpectedly contain warnings urging recipients to delete the e-mail.
The alerts are issued by ImageShack, in an effort to stop spammers using its services.
It is replacing pictures, known to have appeared in spam, with warnings such as Do not buy.
Spammers often use image hosting sites so they can include fake logos, intended to make the mail look genuine.
The aim is raise users' awareness of the problem and to make life difficult for those sending the spam, Alexander Levin, president of ImageShack told BBC News.
The net effect is that the spammers lose customers and see a decrease in revenue.
Link: http://www.bbc.co.uk/news/technology-12450348