That and doing on-line research. Some years ago I did some light research on condos and have been getting periodic mailings with statements like "Save big on fees for your condo" or "Sell your condo through us"....never talked to anyone, or even looked at any - just did some on-line browsing...
If thinking lawsuit - you probably have even less on "whoever" than Mueller has on Trump....
Browsing history is sold now much as catalog mailing lists have long been sold. It’s an indicator of potential interest to marketers and manufacturers. They don’t know the first thing about you personally other than that “marker” of potential interest indicated via your browsing history. Where it can get scary is when it’s compiled with other indicators, financial data which is sold, zip code, income, medical history, etc. at which point a fair amount about you personally can be known, but even then they’re typically not interested in you per se, they’re interested in selling something. Nefarious uses are certainly possible, however.