Reuters reports that along with banks and pharmaceutical makers, eBay and PayPal are among the brands most targeted by phishers.

It makes sense then that Yahoo and eBay (and its PayPal service) are to team up to block fake emails to users from phishers claiming to be eBay or PayPal, that try and trick folk into giving out their personal info.

eBay and PayPal have upgraded their computer systems to support "DomainKeys" invented by Yahoo that authenticates email senders are who they say they are, which allows Yahoo to block fake emails.

The technology upgrade will be made available to Yahoo Mail users worldwide over the next several weeks, the company said.

"It is a big step forward for consumers in defense against the bad guys", John Kremer, vice president of Yahoo Mail.