NIST recommends that when users are trying to set a password you should reject those that are commonly used or compromised:
When processing requests to establish and change memorized secrets,
verifiers SHALL compare the prospective secrets against a list that
contains values known to be commonly-used, expected, or compromised.
But how do you know what are the compromised passwords? Luckily Troy Hunter put a lot of effort into building the "Have I Been Pwned (HIBP)" database with the SHA1 hashes of 501,636,842 passwords that have been compromised on the internet. Sweet.