Big problem: authors often support claim X with with a citation to paper Y, even though Y has no bearing on X or even directly refutes X.
Estimates suggest that between 5% and 35% (the latter seems too high to me) of scientific citations do this. It's a grave sin, akin to claiming statistical significance when you clearly don't have it. Yet it's very common.
An extreme case: the first citation in the new FLI letter "Pause Giant AI experiments".
@timnitGebru explains: https://fediscience.org/@timnitGebru@dair-community.social/110110514822795454