Data caps may be the next frontier in the battle over net neutrality.
Rep. Anna Eshoo, the top Democrat on the House Communications and Technology Subcommittee, warned Tuesday that cell-phone carriers and home Internet providers could use caps to restrict access to certain online services.
When subscribers reach their monthly data allowances, some Internet providers impose overage charges, while others throttle speeds or temporarily suspend service.
The California Democrat noted that much of the debate over net neutrality has been focused on the possibility that Internet providers could charge websites for access to special "fast lanes."
"Data caps, particularly when they're applied discriminatorily, could have the same damaging effect on the free and open Internet as we know it," Eshoo said.
She worried that broadband providers could use caps to discourage people from watching online video services such as Netflix and Amazon Prime. The Internet providers may want to ensure that people keep subscribing to pricey cable-TV packages.
In fact, a Government Accountability Office study found that some people stream less online video to ensure they don't go over their monthly limits.
The agency unveiled the preliminary findings of its investigation into data caps at a Capitol Hill briefing Tuesday with Eshoo. GAO plans to release a final report in November.