[nokcha]

>DMCA takedown notice is a legal threat.

I think Drew was mistaken when he called it a "takedown notice". That term has a specific meaning, and judging from the linked article, what DropBox actually sent to the OP was not a takedown notice. Instead, it was just a message saying that DropBox had received such a notice from a third party and consequently disabled access to the allegedly infringing file.

[dhouston]

correct -- fixed this distinction in my reply, thanks