Google is being sued in the US by a Safari user who alleges the company willfully and knowingly violated wire-tapping laws.

Matthew Soble, from Illinois, filed the complaint this week in a court in Delaware, Bloomberg Businessweek reports.

The complaint surrounds Google's use of tracking cookies that attach itself to the Safari browser and track users' web activities. Safari take a notoriously aggressive stance on cookies, but Google got around Safari's privacy restrictions by exploiting a loophole that allowed the search giant to install a temporary cookie if a user clicked a +1 button embedded in online adverts.

According to Soble, Google has "knowingly circumvented" Safari's cookie restrictions and this violates federal wiretapping laws and other computer-related statutes, the lawsuit claims.

Google hasn't commented on the lawsuit, but did tell Macworld's sister title PC World earlier this month that it hadn't intended to track Safari users and only wanted to know when a user was logged in to their Google account.

"We used known Safari functionality to provide features that signed-in Google users had enabled," said Rachel Whetstone, Google's senior vice president of communications and public policy.

"If you were logged in, Google could then deliver personalized advertising and perform other functions, such as sending +1's back to a user's Google+ social networking profile.

"However, the Safari browser contained functionality that then enabled other Google advertising cookies to be set on the browser. We didn’t anticipate that this would happen, and we have now started removing these advertising cookies from Safari browsers."

But lawmakers in the US are unhappy with Google and have asked the Federal Trade Commission (FTC) to investigate. Meanwhile, Microsoft has claimed that Google circumvents privacy protections built in to Internet Explorer too, though Google argues that Microsoft's browser has an impractical privacy policy.