A few months ago, Sen. Patrick Leahy (D-Vt.) asked a number of Internet providers to vow that they'd never set up controversial Internet "fast lanes" where some Web sites would get sped up over others. So-called "paid prioritzation," he said then, would divide the Internet into haves and have-nots. The ISPs should commit to swearing off such fast lanes, Leahy said.

But in their responses, the companies — Comcast, Verizon, AT&T, Time Warner Cable and Charter — didn't give him the promise he was looking for. So now, the Vermont Democrat is calling them out for an "unfortunate" failure to comply.

"This is disappointing," Leahy said in a statement Friday. "I was disappointed that some Internet service providers in their responses brushed aside these concerns dismissively."

Although the ISPs told him they didn't currently have plans to engage in paid prioritization, they declined to rule out starting such programs in the future, as Leahy asked.

Leahy's request was unlikely to ever lead anywhere significant; the whole reason broadband companies are fighting federal regulators on net neutrality is because many would like the freedom to engage in paid prioritization if they wanted to. It wouldn't make sense for them to box themselves into a corner. So the chairman's move was largely symbolic.

Still, the ISPs' silence on paid prioritization speaks volumes about their intentions.

Read Leahy's full statement here. Here also are his initial letters to the Internet providers, and their responses. I've asked the companies involved to comment, and will update if and when they reply.