Verizon, the largest mobile carrier in the United States, is being accused of violating net neutrality rules by throttling the speed data used by streaming video applications on its mobile network.

The complaint comes from digital rights advocacy group Free Press, which is asking Verizon customers and those who support current net neutrality rules to sign a petition asking the Federal Communications Commission to investigate the telecommunications company.

Read: Net Neutrality Day Of Protest: Tech Companies Come Together In Major Push To Save Internet Equality

The petition comes just one day after Verizon admitted to throttling video traffic on its network in a statement to trade publication Broadcasting & Cable, presenting the practice as “reasonable network management.”

"Video optimization is a non-discriminatory network management practice designed to ensure a high quality customer experience for all customers accessing the shared resources of our wireless network,” a spokesperson for Verizon told the publication.

Verizon came clean about its wide-ranging video throttling after users of the mobile carrier started to observe their data speeds slowing down while trying to use Netflix and the Netflix-operated speed testing site Speeds on the services capped out at around 10 Mbps.

While the speeds are generally enough to allow for video playback at 1080p quality, the cap also goes against net neutrality rules which forbid internet service providers from discriminating against any type of data including blocking content, throttling or slowing speeds, and offering paid prioritization that favors services willing to pay for preferential treatment.

Read: Is Net Neutrality Dead? What The Internet Will Look Like Without Open Internet Rules, Title II

Net neutrality rules have come under fire by current FCC Chairman Ajit Pai—a former Verizon lawyer—who has proposed a plan that would roll back the protections and potentially undo the bright light rules of net neutrality.

However, the rules passed by former FCC Chairman Tom Wheeler during the Obama administration, which reclassified the internet as a common carrier under Title II of the Communications Act, are still in place for the time being.

According to Free Press, Verizon has violated those rules. While the FCC does allow for “reasonable network management,” the advocacy group said Verizon’s actions do not fall under that exception.

“Slowing down video, and only video, doesn't make a whole lot of sense,” the group said. “If Verizon's network can handle traffic, it can handle traffic—whether it's video or not. That's why the Net Neutrality rules allow for network management—but prohibit companies from cherry-picking which apps work and which ones don't.”

It is not clear if the FCC would choose to respond to the petition from Free Press, even if it generates a considerable number of signatures. The commission under Chairman Pai has appeared uninterested in enforcing net neutrality rules, especially in the face of its apparent repeal despite considerable public pressure to keep the rules in place.

According to a recent poll conducted Freedman Consulting, Americans overwhelmingly support current net neutrality protections. The poll found 77 percent of Americans—including 73 percent of Republicans, 80 percent of Democrats, and 76 percent of independents—want to keep net neutrality protections. More than eight in 10—81 percent— of people said ISPs should not be able to block websites, throttle or slow connections, or offer paid prioritization.