Facebook Inc. has come under fire again over privacy concerns, this time for allegedly scanning personal information in private Facebook messages that is then used for targeted advertising.

Facebook’s bid to dismiss a class-action lawsuit originally filed in 2013 was shot down by U.S. District Judge Phyllis Hamilton, meaning the social media giant must face the lawsuit in court.

The lawsuit claims that Facebook used mentions of websites in private messages as a tally of “Likes,” which the site then used to display targeted advertising to those users.

Facebook is not the first service to use the content of messages to cater advertising to users. Google Inc.’s Gmail would scan emails for key words to display unobtrusive text ads in a banner above the message.

But Google’s method for scanning information and displaying ads was automatic and was not stored for future use. There was no personal file for each user saying what sorts of website they talked about. Google’s system would catch certain words in the message and display ads relating to those words, but it did so on-the-fly without storing the information.

Where Facebook’s systems supposedly differs, and the reason it is currently under scrutiny, is the information taken from the private messages is saved and used to create a “user profile” to cater ads over time. Effectively, this means that Facebook kept the tallies of the websites each person talked about on file and used that information to display ads on a longer time frame.

Technically, this tactic could be permitted by the Terms of Service to which Facebook users must agree when they sign up for an account. Facebook claimed that their actions were allowed under the federal Electronic Communications Privacy Act, which permits the use of private user information as required in the daily course of business.

But Judge Hamilton denied this reason for dismissal. “[Facebook has] not offered a sufficient explanation of how the challenged practice falls within the ordinary course of its business,” Judge Hamilton said.

Facebook no longer scans private messages in this way for advertising, but it does still track them for anti-virus purposes.