MI 4 RSE?
TLDR: don't share passwords across valuable sites.
My main worry is the users are lazy and re-use passwords across different websites.
For example, if used the same password here as you do for Amazon, then it may have been visible (from this site) to nefarious folks who then stash it away. At some later date they may try that email and password combi against other sites (Amazon, banks, etc) - ones that contain monetary value, or more interesting personal data.
If you want to scare yourself just visit this site - it's a safe site - and enter your email address.
It tells you how many known data breaches contained that email address:
https://haveibeenpwned.com *
In my case I have two entries in there, but I know both the passwords compromised aren't my banking/vital website ones, so I should be OK.
*'pwned' = 'owned'. It's a classic gamer typo about capturing/dominating opponents, and nothing to do with pawn, porn, etc.