Re: Not the point
The news site your talking about didn't talk about it, they gave detailed instructions on how to hack the software which isn't the same thing. Also, the car example is totally bogus, since the DCMA doesn't apply even remotely. The paper example works depending on the software you're using. Some software, like MS Word, can be told to print 2 sided on a single sided printer and it tells you when to turn the paper over and sometimes even what direction.
There are probably legitimate examples of companies suing to stop legitimate disclosures, but there aren't any in your comment and you misunderstood what happened at the Hackaday.com site. They were issued the takedown specifically because they "posted instructions for how to hack [Tektronix'] modules and thereby violate Tektronix’ copyrights" as they detailed in a later posting. The reason hackaday posted the instructions in the first place was because the security of the "key" was astoundingly unsecure and hackaday modified the post to remove the specific instructions while still reporting the actual story of the horrible security snafu that was the key.