An April 26 letter to Federal Communications Chairman Ajit Pai —signed by more than 800 tech startups, investors, and entrepreneurial support organizations from all 50 states—argues against plans to weaken net neutrality rules.

Net neutrality is the concept that Internet service providers should enable consumer access to available content and applications without either blocking or giving preferred access to specific content providers.

“The success of America’s startup ecosystem depends on an open internet with enforceable net neutrality rules, ensuring that small companies can compete on a level playing field without the threat that their services will be discriminated against by big cable and wireless companies,” the letter says.

“The success of America’s startup ecosystem depends on more than improved broadband speeds,” the letter to FCC Chairman Ajit Pai says. “We also depend on an open Internet—including enforceable net neutrality rules that ensure big cable companies can’t discriminate against people like us. We’re deeply concerned with your intention to undo the existing legal framework.”

“Without net neutrality, the incumbents who provide access to the Internet would be able to pick winners or losers in the market,” the letter adds. “They could impede traffic from our services in order to favor their own services or established competitors. Or they could impose new tolls on us, inhibiting consumer choice.”

In 2015 the FCC put in place light touch net neutrality rules that not only prohibit certain harmful practices, but also allow the Commission to develop and enforce rules to address new forms of discrimination, the letter explains, expressing the signatories dismay over reports that Pai wants tp replace this system with a set of minimum voluntary commitments.

This, they wrote, “would give a green light for Internet access providers to discriminate in unforeseen ways.”

“Rather than dismantling regulations that allow the startup ecosystem to thrive, we urge you to focus instead on policies that would promote a stronger Internet for everyone,” the letter concludes. “We applaud efforts to remove unnecessary barriers to construction of new networks, which would foster increased competition and faster, more affordable, open Internet access.”