On my side-project todo list, I have an idea for a scientific service that overlays a "trust" network over the citation graph. Papers that uncritically cite other work that contains well-known issues should get tagged as "potentially tainted". Authors and institutions that accumulate too many of such sketchy works should be labeled equally. Over time this would provide an additional useful signal vs. just raw citation numbers. You could also look for citation rings and tag them. I think that could be quite useful but requires a bit of work.