Pretend to work, or were incompetent.
Similar things happened to me too. Could finish day’s work in an hour. It was a small company, didn’t have extra work they could give me, didn’t like I was idle most of the time since we had co-working space. And didn’t increase my salary even through they said they’d increase based on performance on provisional period.
They finally increased salary after 9months (said they’d do it in 3-6), and it was nominally higher like everyone else. Resigned the next day. When I went back few months back to get something every face was new one except the upper management and their family.
So basically they count on people to leave in a year or two, so they can hire other batch of fresh graduates in low salary again.
I think it’s mostly because European are more aware of privacy, open source and such. I see that trend here and in many open source projects, and I browse on US times.