The web of corporate intrigue that powers watchdog groups is remarkable. The people who caught the professors are from the Campaign For Accountability, a "watchdog group" [1]. They pursue this role for a variety of issues. Their work on Google comes from a wider initiative they call the Google Transparency Project. One of the funders of said project is Oracle [2], which has...its own motives for bringing Google down a peg [3].
[1] https://campaignforaccountability.org/
[2] https://fortune.com/2016/08/19/google-transparency-project-2...
[3] https://en.m.wikipedia.org/wiki/Google_v._Oracle_America