Note: I was once followed by the FBI because they were following someone I was spending a lot of time with. I ended being asked for a coffee by the agent. I was not worried because I had nothing to hide.
Now what's the difference between me and the government? In this case, nothing, because neither one of us has any legitimate interest in what you say or do, short of suspicion of a crime.
A better argument might be that you should always want to minimize contact with any government, because they have power over you and they make mistakes. The costs to you for a mistake could be huge: imprisonment, loss of time, loss of money, loss of reputation. All for a mistake.
Never touch the government unless absolutely necessary.
In other words, where is the line to what is or is not the government's business, and why does the government get to determine where this line is?
gov·ern : Conduct the policy, actions, and affairs of (a state, organization, or people).
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.
please google : why you shouldn't talk to the police
Mr. Jefferson, what do you have to hide? You're not doing anything illegal are you?
Recent news make me believe that there has been no lesson learned from anything. Right-wing terrorists sponsored by the Verfassungsschutz, Bundestrojaner, police violence, and Voratsdatenspeicherung. And most of the population does not even care about any of this. The only thing that people seem to have learned is how to hide aspirations to power and control behind some thin veil of democracy.
https://encrypted.google.com/search?q=nothing%20to%20hide%20...
(Would link you to it directly but the site appears down; the search results may find a mirror, but watch out for links that are essays about the paper rather than the paper itself.)