I was one of the 65 million Dropbox users whose accounts were hacked in 2012. Dropbox didn't admit the breach, which included passwords, for several years. I deleted my account but I can see that even now the email address I registered with them still receives a lot of spam.
I created a new account (with of course different credentials) in 2017 and have had no problems since then. I hope they have learnt a lot about security.
1980 Royal Ivory 4/4 4-seater. B4771