The reason I put this here is to focus more on whether it is against the law in your country or not to 'advertise investigative services capable of digging up personal information' rather than the methods used to obtain the information which in this case is via online.
International Level: International Guru / Political Participation: 3231 100%
This type of thing really bothers me. I can put a phone number on the google.com website and find the name and address of the owner of the phone number. Other sites allow you to get everything on people from social security number to addresses and phone numbers. This should be against the law because it totally violates my right to privacy, and someone could really do some bad things with the information that anyone can get.
Protecting web users' privacy
A new system has been developed that uses function secret sharing to disguise database queries during web-service transactions. The system could prevent price gouging and unwanted user profiling. Ref. Source 2k.
So, I'm not the expert here by any sense of the imagination, but I believe it depends on how the site obtains the information. Congress and the courts long ago decided that what we put on the internet is public domain. As much as we dislike that thought, I think it settled law. So, if the site is obtaining this information off of public sites and sites that we probably, unknowingly, allowed to publish our information when we agreed to this or that app or program. There is more of our information out there than we know because we agree to these 65 page long contracts when we sign up for this or that and buried in there almost always is that they can sell our information. On the other hand, if these sites are getting our information from places that obtained it illegally, they are in trouble.
Edited: Abnninja on 27th Mar, 2017 - 2:51pm
I think most places you go to shop online anymore uses your personal information to send you ads to get you to buy certain things that you have looked at and shown a interest in. Pretty much nothing is sacred on the internet anymore and many will use your information and sell it to others.
I long ago started sticking false information into any website I didn't feel warranted the real stuff. I may not be able to stop them from disclosing private information to others, but at least I can confuse the dickens out of anyone trying to build a profile based on it.
Daishain,
You are a smart man. I started doing that a while ago too when a friend of mine suggested it. There is also some false information out there on me due to the nature of the work I did in the military… so I may be in slightly better shape than the norm, as you seem to be. Do you see a way to recover from this, both as an individual or as a society? I don't other than a complete rewrite of the laws, which I don't see happening anytime soon.