If the nature of the DB isn't open ended && subjective, you avoid lots of landmines.
You can also avoid the landmines if you have a mechanism for attributing content to specific users as Fluidinfo does via namespaces. There can only be one Wikipedia page for Transformers 3, so there might be a lot of contention about whether the article was fair/neutral, but in Fluidinfo you, RottenTomatoes, IMDB, and anyone else can place a rating or review tag on the object about Transformers 3, without any conflicts.
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If the nature of the DB isn't open ended && subjective, you avoid lots of landmines.
You can also avoid the landmines if you have a mechanism for attributing content to specific users as Fluidinfo does via namespaces. There can only be one Wikipedia page for Transformers 3, so there might be a lot of contention about whether the article was fair/neutral, but in Fluidinfo you, RottenTomatoes, IMDB, and anyone else can place a rating or review tag on the object about Transformers 3, without any conflicts.