Opposition to net neutrality dominated the second round of the Federal Communications Commission's comment period, according to an analysis from the Sunlight Foundation, a government transparency nonprofit.
Those comments — making up about 60 percent of submissions — came nearly exclusively from form letters originating from a group calling itself American Commitment.
The first official comment period ended in July, while the second one ran through mid-September.
Combined, about 41 percent of comments were against net neutrality, while the others were either in support of it or a clear position could not be determined. About eight in 10 comments were form letters — significantly higher than the first round alone.
The FCC said 3.9 million comments were submitted in total, the most input ever recorded by the commission. The Sunlight Foundation, however, counted far fewer.
"As was true in round one, we fail to see how the FCC arrived at the count that was widely publicized," the Sunlight Foundation said, noting it counted about 1 million fewer comments in the second round alone.
Pro-net neutrality group Fight for the Future alleged the FCC failed to log 150,000 comments submitted by it, Demand Progress and Free Press. It also called the Sunlight analysis flawed because it was unable to process a large portion of the comments.
Without the net neutrality opposition campaign from American Commitment, the totals from the second round would look largely the same as the first round, with only about 4 percent opposing net neutrality.
FCC Chairman Tom Wheeler outlined proposed rules earlier this year, and will likely issue finalized rules in the next few months.
President Obama and other advocates have urged the FCC to use the strongest possible authority to prevent Internet service providers from blocking or slowing service to any website, while also preventing companies from striking deals for faster service.
Those advocates have called for the commission to reclassify broadband Internet as a public utility, something Republicans and Internet service providers have fiercely resisted.
— Updated Dec. 17 with reaction from Fight for the Future