The fact that screenshots of those calendars were later found outside the company, helps to demonstrate intent here.
Also, it might be legal for me to follow a person around in public and film them, but doing that is still incredibly creepy and indicative of mal intent.
At some point those behaviors cross the line into stalking. I don't know where exactly law enforcement and prosecutors draw that line, but I'd prefer to get them involved sooner rather than later.
Different groups may follow you. PI trying to determine marriage issues, health issues for insurance reasons, etc
If you are famous or have something to add to the news cycle reporters or people trying to sell your picture may follow you around.
Most people post where they have been publically to create their personal brand that they share with others.
These have no mal intent. The overused word creepy is subjective.. and doesn't make it wrong. I know someone who feels creepy going outside at night. We shouldn't morally make a judgement for everyone based on someone's feelings. I don't think going outside is creepy.
Sure - but maybe you have ill intent towards others (filing dubious claims, an affair without spousal approval, etc.) and this is to see it happen. It is no different than police doing a stakeout - it is just a private citizen than a public defender.
If insurance companies could not investigate your insurance would cost 10 times as much.
The marriage investigation is a mixed bag. If you are running a drug running operation I should get the kids and you need some proof to make that claim.
Also, it might be legal for me to follow a person around in public and film them, but doing that is still incredibly creepy and indicative of mal intent.