This contradicts your earlier statement -- that you removed the file from the person's account.
I'm on your side here, but you need to be as transparent as possible here. Are you also saying that your system automatically generates emails that make false claims about having received a DMCA takedown notice?
This whole situation is pretty revealing about Dropbox. If hosting software that COULD be used to violate the TOS were also a violation of the TOS, and if Dropbox had been in the practice of banning such files, then 2 outcomes would have obtained:
1. The system for banning files would not send out copyright infringement notices automatically. It would be set up for banning things like source code that could be used to violate the TOS.
2. Someone on the support team you claim the system was designed for, would have done the ban, instead of you having to come in and implement "higher-level business logic" by using the ban system for something besides copyright violations.
Despite that, I'm reading your terms of service, and it sounds to me like you reserve the right to terminate service (which sounds like it would include deleting files) with or without notice, if you deem there has been a sufficiently egregious violation of your ToS.
I don't understand why you would bother? If they still had the file, wouldn't they be quite able to post it elsewhere? Why the censorship? I'm not comfortable in the knowledge that Dropbox can willy nilly refuse to allow me to share files on a case by case basis.
I can understand dropbox not allowing you to publicly share files on a case by case basis, or else I could simply put illegal content in my public folder and send out the link.
I understand it a little less if you are say sharing folders between friends.
And I wouldn't like it at all if they deleted something from my dropbox, but it seems we aren't there yet.
I'm on your side here, but you need to be as transparent as possible here. Are you also saying that your system automatically generates emails that make false claims about having received a DMCA takedown notice?