social bookmarking is delicious

So after looking at delicious I have come to the conclusion that some bookmarks are better than others.  For researching or helping to create an information web around a topic or related topics this is brilliant.  The problem? Who looks at the links to make sure they are of value?  Some of the links were great under the library setting.  Others were horrendous garbage that was bookmarked by multiple people and whos application was limited.  Great tool but it depends on how it is used.