This is a very non-standard and unique thing Dropbox has done. Dropbox's concerns for their users are: 1. legacy accounts with bad passwords 2. people who use

This is a very non-standard and unique thing Dropbox has done. Dropbox's concerns for their users are: 1. legacy accounts with bad passwords 2. people who used bad passwords then and have not changed it The people who are helped are people who had bad password hygiene and now have good password hygiene. What it doesn't fix is people's legacy accounts who don't log in anymore. In my opinion it would be far more helpful to: 1. lock accounts that have not been logged in for a long time. 2. push users in the right direction who still do log in by analyzing password complexity etc. That way you don't punish people with great 34 character passwords.