For me it's mostly because serious power abuse is coming in many cases from governments. A government is never just an impartial entity but always consists of people with subjective motives. States abusing the power they have when they can invade the privacy of their citizens is just way more common than states falling into anarchy because of insufficient control over it's citizens.

Also people often do things which might be illegal although the moral legitimation for making those actions illegal is at least very questionable. Think about stuff like abortion laws (legal now in Germany, but was illegal not so long ago - so with the same tech states could have checked who visits abortion clinics), certain drug laws (many weak drugs are still illegal in Germany), laws about censorship (especially youth-protection is occasionally very strange in Germany), etc.