Alphabet Inc., in which the company is accused of violating antitrust laws in order to develop an already dominant advertising business.

Alaska, Florida, Montana, Nevada and Puerto Rico joined the lawsuit filed in December, Texas Attorney General Ken Paxton said. Thus, the number of plaintiffs has reached 15 states and territories, reports Reuters.

The lawsuit was one of three filed last year by the federal government or states against Google.

The lawsuit alleges that Google is quietly teaming up with its closest online ad competitor, Facebook, and is using an excuse to protect user privacy to act unfairly. Publishers complain that one of the results has been a drop in revenue. Facebook and Google are working together to identify users who use Apple products.

Google, in a statement, described the new claim as a gratuitous addition to an already unfounded lawsuit.

The lawsuit notes that starting in 2015, Google can view WhatsApp messages that users back up to the Google Drive cloud storage system.

Google knew that users were not informed about its access, but "did nothing to correct this misunderstanding, the lawsuit says. By June 2016, Google D had attracted nearly 250 million new users through its partnership with WhatsApp.