Google is making headlines this week for a court filing that some have interpreted as an admission that Gmail users should have no expectation of privacy while using the service.

The statement came as part of a motion to dismiss a class-action case that accused Google of violating federal and state wiretap laws via a program in Gmail that scans emails to serve up targeted ads.

Google argued that "just as a sender of a letter to a business colleague cannot be surprised that the recipient's assistant opens the letter, people who use Web-based email today cannot be surprised if their communications are processed by the recipient's ECS [electronic communications service] provider in the course of delivery."

The search giant goes on to quote a 1979 case, Smith v. Maryland, which found that "a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties."

In that case, a telephone company, at the request of law enforcement, installed at its central offices a pen register to record the numbers dialed from the telephone at the petitioner's home. Ultimately, the Supreme Court found that "the installation and use of the pen register was not a 'search' within the meaning of the Fourth Amendment, and hence no warrant was required."

According to public interest group Consumer Watchdog, however, the filing means that "Google has finally admitted they don't respect privacy."

"People should take them at their word; if you care about your email correspondents' privacy don't use Gmail," John M. Simpson, Consumer Watchdog's Privacy Project director, said in a statement.

Ad-related email scanning within Gmail is nothing new; it dates back to at least 2004, and has encountered a number of challenges along the way. Google has long held that the scanning is done via an algorithm and no humans at Google are reading peoples' emails.

Google declined to comment further on the matter. But it seems the point of contention is the data that people voluntarily turn over to third parties and what that means. In its motion to dismiss, Google discusses this at a high level – as in data traveling over a network.

"All users of email must necessarily expect that their emails will be subject to automated processing," the firm said. "As numerous courts have held, the automated processing of email is so widely understood and accepted that the act of sending an email constitutes implied consent to automated processing as a matter of law."

Consumer Watchdog interpreted that to mean "that people can't expect privacy when sending a message" via Gmail. But the filing discusses non-Gmail users who send messages to Gmail users – who should expect that their messages will be processed by Google. Basically, those people should have no expectation that messages they send to a Gmail account will not be handled by Google technology.

Google also referred to another case, which held that "by the very act of sending a communication over the Internet, the party expressly consents to the recording of the message."

With all the news surrounding the National Security Agency data leaks, that should come as no surprise. Major tech companies are required to retain certain data for varying lengths of time in case it is requested by law enforcement.

The controversy recently prompted two encrypted email services to shut down in order to avoid government scrutiny: Lavabit, which was linked to NSA whistleblower Edward Snowden; and Silent Circle.

For more, check out 6 Tips for Protecting Your Email Privacy.

Consumer Watchdog is no stranger to Google, meanwhile. Back in 2010, the group purchased space on a Times Square jumbotron to display a video that attacked Google's Eric Schmidt and his company's privacy policies. The Times Square ad, projected on a 540 square foot screen, was a 15-second animated short featuring a bobble-headed Schmidt as an evil ice cream man. "He's collecting YOUR personal information," a message said.