Can't believe it's someone's job to make this list and this is what they came up with. A 14-year-old with internet access could name way more major players.
As it is not mentioned by OP : anime site it's speaking about is HiAnime.
Excerpt :
HiAnime, the world's biggest anime piracy streaming site, is now one of the newest additions to the U.S. government's annual list of notorious piracy and counterfeiting markets.
Thanks! Been looking for a good one since 9anime died. Glad the government did all the work in finding and recommending replacement. Been hopping around for a while.