A Philadelphia woman is suing Google over emails she sent to a friend's Gmail account that spawned content-related ads.

The suit echoes several filed around the country by class-action lawyers who say the practice violates wiretap laws in some states.

In court filings in Maryland, Google admits it routinely scans emails for spam and computer viruses, but says that's permitted under similar federal wiretap laws.

Google argues that selling advertising is likewise a routine business practice permitted by law. And Google says Yahoo! and other email providers sell similar ads.

The Philadelphia plaintiff, Kristen Brinkman, says she doesn't have a Gmail account and never signed the company's acceptance policy. She filed her federal lawsuit Nov. 30.

Her lawyer, Richard Golomb, says email privacy is crucial given its widespread use.