How does uptolike, intarget work? And what to do with it?

Question

Social media

Hello!
There are services on the Internet - uptolike, intarget. How do they work? How can I legally get the address of a page on the social network of a person who has visited my site?
And if the services work illegally and collect information using viruses / web attacks, then what to do about it? How to counteract / achieve blocking of their domains / hold them accountable?
After all, if they centrally infect user sites / machines with malware that conducts tracking, then at least there is a fact of illegal access to information, right? (the address of my social network profile, which is not available to all sites by default / my browser history / ...)
UPD. Someone writes that data is bought from social networks. networks. Then the question - a social. How do the networks know what other sites I visit besides them? (well, it is understood that I do not leave this data anywhere on the social network)?