DRM is definitely a big offender, the other one off hand that is amazing is anti-cheat systems. Both types of technology for PC games basically are predicated o

DRM is definitely a big offender, the other one off hand that is amazing is anti-cheat systems. Both types of technology for PC games basically are predicated on the concept of "if we monitor everything it's remotely possible to monitor about your PC, we can detect if you do something bad with it". It's probable that Steam would not be remotely as successful if it interfered with DRM and anti-cheat strategies on privacy or security grounds.