You're probably talking about https://adnauseam.io/

Also https://news.ycombinator.com/item?id=19278936

Sounds like TrackMeNot[0], which constantly searches for random things on various search engines, or AdNauseum[1], which clicks every ad it sees.

[0] https://cs.nyu.edu/trackmenot/

[1] https://adnauseam.io/