Opponents of the U.S. Federal Communications Commission’s new net neutrality rules aren’t giving up, with a conservative advocacy group saying it has collected more than 540,000 signatures on a petition asking Congress to overturn the agency’s action.

American Commitment, a group with connections to Republican billionaire brothers Charles and David Koch, delivered those petitions to Congress this week. Each petition went to the three members of Congress, one representative and two senators, representing the person signing the letter, American Commitment said.

“The landslide 2014 elections made crystal clear that the American people reject larger, more intrusive government,” the Web form leading to the letters says in part. “But President [Barack] Obama reacted by moving even further left, ignoring the fact the Federal Communications Commission is supposed to be an independent agency, and openly demanding the FCC take the most radical action imaginable: reducing the Internet to a ‘public utility,’ imposing sweeping new taxes and destroying private investment, competition, and innovation while putting bureaucrats firmly in control.”

The American Commitment Web page appears to overstate some information related to the net neutrality debate of the past year. The actual letters sent, in some cases, use more moderate language, but one letter calls the FCC action “reckless,” and another letter calls net neutrality supporters “extremists.”

In November, Obama called on the FCC to pass net neutrality rules that reclassified broadband as a regulated common carrier. He also noted then that the FCC is an independent agency. “Ultimately, this decision is theirs alone,” Obama said then.

And while some opponents of the FCC’s rules fear the regulations will allow new taxes on broadband and limit some private investment in broadband networks, it’s uncertain whether those predictions will come true. Some studies predicting billions of dollars in new broadband taxes tie the FCC’s net neutrality action to a separate proceeding at the agency examining whether broadband providers should pay into its Universal Service Fund. The USF is pool of money that helps subsidize telephone service and now broadband in rural areas.

Net neutrality advocates argue that the rules, prohibiting broadband providers from selectively blocking or throttling Web traffic, will actual spur investment in Web-based services.

Still, American Commitment said it was encouraged by the response of its members. The 3-year-old organization has “never seen such an intense citizen response in opposition to a federal regulatory action,” Phil Kerpen, president of American Commitment, said in a statement.

Earlier this year, Republican leaders in Congress proposed legislation that would overturn the FCC’s reclassification of broadband as a regulated common carrier while retaining some basic net neutrality protections. With widespread opposition from Democrats, that legislation hasn’t advanced, but American Commitment said it was encouraged this week when Representative G.K. Butterfield, a North Carolina Democrat, called on Congress to craft net neutrality rules.

The petitions are just one effort to overturn the rules. This month, trade group USTelecom and ISP Alamo Broadband filed lawsuits challenging the FCC’s new rules.

While American Commitment rallied opponents of the new regulations, net neutrality supporters haven’t been silent.

During a week-long stretch this month when FCC officials faced five congressional hearings, supporters of the new rules placed 25,000 calls to Congress asking lawmakers to back the FCC action, according to the groups organizing the effort. Organizers included Free Press, Demand Progress and Fight for the Future.

Earlier this month, more than 140 companies and organizations sent a letter to the FCC, thanking commissioners for their Feb. 26 net neutrality vote. A second letter supporting the FCC, sent to members of Congress, came from about 40 civil and digital rights groups.