Also Libreoffice Writer: I use it for the very same purpose (and then imagemagick resulting pdf to a flat jpg: voilà, "scanned paper document" is ready!)

but if you're using some cryptographic factor no attacker will be able to go through it *) )

*) sure, it had to be applied properly😅

otherwise we either don't get a new user or will heaven a burden on a tech support);
- from a threat modeling perspective the main issue here is a password reuse (i.e. something like credentials stuffing from an attacker perspective); you cannot fix it reliably at server side with passwords only2/3

Looks like we are observing this issue from different vantage points:
- I believe that security part has to complement the organization's goal (i.e. in this case to ease a new user registration process a clear error message is required; 1/3

It is not: "create a new account" scenario will provide those anon users with the exactly same info.