Stanford Law Professor Barbara van Schewick, who has consistently argued for stricter net neutrality rules, wrote in a blog post on Thursday that “harmful 5G fast lanes are coming.”

“T-Mobile, AT&T and Verizon are all testing ways to create these 5G fast lanes for apps such as video conferencing, games, and video where the ISP chooses and controls what gets boosted,” van Schewick wrote. “They use a technical feature in 5G called network slicing, where part of their radio spectrum gets used as a special lane for the chosen app or apps, separated from the usual Internet traffic. The FCC’s draft order opens the door to these fast lanes, so long as the app provider isn’t charged for them.”