"The lady doth protest too much," says Queen Gertrude in Act III of Hamlet, and she might as well be talking about the residual textual outcome of many Wikipedia edit wars. We're talking about "Citation overkill".
Sometimes when a fact is disputed on Wikipedia, an editor who feels very strongly they are right will not just add one or two citations to overwhelm their editorial opponents. I must be right, look at how many sources support me!
Whether these sources truly support the position is a different question, and usually the dispute on Wikipedia reflects a dispute in the real world. Oftentimes, citation overkill situations are the result of a stalemate in an editorial disagreement, and it will remain unresolved until time elapses and passions cool.
If you're interested in seeing some examples, you're in luck, because the essay includes several good ones.