A senator in California is making a bid to block Google's Gmail – its high-capacity email service announced on April 1.

Calfornian state senator Liz Figueroa told Reuters she is drafting legislation to block the service because it "represented an invasion to users' privacy".

Like other critics, she objects to the way in which Gmail will scan e-mails for content, inserting advertising in personal messages.

"We think it's an absolute invasion of privacy. It's like have a massive billboard in the middle of your home," she said

According to the Financial Times, Senator Figueroa sent a letter to Google urging the Internet search engine group to discard its plan to scrutinise e-mails, calling it a "misbegotten idea" and claiming that it was advertisers rather than customers who wanted such a programme.

"This 'Faustian bargain' undermines the most fundamental aspect of communication - the expectation of privacy," she said. "The proposal is little different from asking people to let the phone company listen in on their calls and butt in at any tie to say 'This call is brought to you by..."

The FT claims some analysts believe that the fact that Google's computers will "read" subscriber's e-mails in order to serve up targeted advertising would not be a major obstacle to use.

Bloor Research technology analyst Martin Langham told the FT: "Most computer users had already learned to live with a lack of privacy. If you send stuff over the Internet then unless its encrypted you must assume it is open to everyone. There is an increasing loss of privacy in general because everything that you do is electronic and can be captured quite easily."

"Google already interprets your searches, but it would need to offer safeguards that information from Gmail wouldn't be passed on to others," he added.