They were crawling the web for mp3s the same way that Google does. Though admittedly Google hides the mp3s much better nowadays then they used to. And the web is way more balkanized into all these corporate walled gardens so there are fewer free roaming mp3s on random websites as there used to be. But technically it was a search engine the same as Google. It always bothers me that this area of the law seems to be ent…
Ironically I'm writing this listening to YouTube streaming in the background: a far superior free way to locate and listen to music without paying for it than most of the early pirate platforms ever could have hoped to be.