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 entirely based on judges' interpretation of the purpose of a UI. A UI is illegal if it guides the user towards the illegal action. If it is possible to perform the illegal action but the user has to put in a little thought into how to accomplish it then the UI is legal. Google can't have a file-type search box with an mp3 option but if users know the right incantation they can achieve the same thing. So we have lawyers telling us how we can build UIs. It seems wrong and like a dangerous slippery slope.
It always bothers me that this area of the law seems to be entirely based on judges' interpretation of the purpose of a UI. A UI is illegal if it guides the user towards the illegal action. If it is possible to perform the illegal action but the user has to put in a little thought into how to accomplish it then the UI is legal. Google can't have a file-type search box with an mp3 option but if users know the right incantation they can achieve the same thing. So we have lawyers telling us how we can build UIs. It seems wrong and like a dangerous slippery slope.