I’m quite happy with my initial use of Firefox Monitor. I’ve recommended it to family, friend, co-workers. I recommend signing up for continuous monitoring. Anyone who has had a password compromise should consider that password and permutations there-of to be public knowledge.
For me the near constant data breaches we’ve seen in recent months is more evidence that strict regulation of retained personal information is necessary in the US and that it would be wise for more websites to consider whether storing passwords is even wise. I have argued that most websites should not be storing user passwords.