NDAs and Contracts That You Should Never Sign
On a similar note, a lot of companies have the audacity to put non-compete clauses in their employment contracts. Typically, this says that you agree not to work for one of their "competitors" or even "potential competitors" (which is never very well defined) for a period, usually 1 or 2 years, after leaving the company.
This is completely outrageous. I signed such a contract at Microsoft without paying too much attention. When I left, I realized that because Microsoft has a finger in everything related to software, technically I could not work in my field AT ALL for 12 months after leaving Microsoft.
Note to self: read this article before signing up for the next gig.