> They can maintain hashes of potentially offensive passwords Assuming they want to check against all casing combinations, the list of hashes would be 3 orders

> They can maintain hashes of potentially offensive passwords Assuming they want to check against all casing combinations, the list of hashes would be 3 orders of magnitude bigger for a list of 7 letter words. If they want to check for substrings or spelling variations, list would combinatorially explode.