Halliburton managed to get audit reports of its Iraq expenses (including $108 million in overcharges) designated as confidential, and thus not subject to disclosure to reporters (or legislators).

DeCSS was originally claimed to be a trade secret.

EFF has a "patent busting project."  What are examples of the most unlikely and most abusive uses of the law of trade secrets?  There's a story here.

Anything a company generates that is the subject of reasonable secrecy-maintaining efforts by the company (and that has economic value because it is secret) can be a trade secret.  Things that aren't copyrightable or patentable may be trade secrets.  Shh.  I'd tell you what's going to happen next, but I can't -- it's a secret.