Nowadays many companies (eg. Google,Amazon,Yahoo) offer webservice API for website to use their data. Many of the APIs serve user generated content at run time. With the API service, one can easily build a search engine on top of it to search their API data. (It just redirects the query to the API, and display the result in a nice way). I know these companies are doing great job to remove illegal content posted by users. My question is if some user posts some illegal text data on Amazon or Yahoo, their API may give the data before people block the content. Is there legal issue on the website which uses the API even it totally has no control over the data?
You also have to worry about the people providing you with an API. Sad world this internet is. http://forums.digitalpoint.com/showthread.php?t=233881