Any and all discussion and information in this post should be taken as professional commentary and analysis for a US-based audience, not legal advice. Nothing on this site should be taken as legal advice. When in doubt, talk to an attorney. When not in doubt, talk to an attorney. Either way, do some research first and have intelligent questions for them. It will save you time, money, and stress.
Every so often in my professional life, I get a Non-compete Agreement across my desk. The vast majority of them are along the lines of "you can't solicit our customers, we can't solicit yours for N months/years". A few are along the lines of "any inside information learned from us cannot be used for anything other than what we authorize".
I find both of these to be reasonable and normally sign them with little – if any – hesitancy.
Then there's another kind of clause… the "you can't support yourself anymore!" clause.
These are just plain nasty. They are no longer about protecting the sensitive information (procedures, customer lists, etc) of the organization, they become a bit more aggressive and go after one's livelihood. They are more focused on limiting what a person (employee, contractor, whatever) can do than just protecting information. This opens a pretty large window for abuse.
From a professional perspective, you should never sign any of these unless you are completely confident and comfortable living bound by these terms. If you sign one of these with their assurance that "this is standard, we never enforce it"… you're taking a huge risk. You're opening yourself up to a huge potential liability that they could sue you at any time, for any reason, or just because they're bored.
The Non-compete that was delivered to me described that I would be banned from providing any services similar to what this organization provides. Their current offerings include: "Web Development", "Blog Design", "Search Engine Optimization", and a variety of related services that CaseySoftware has been providing since 2004 and that I personally have provided since 2000.
If you're interested in hearing a bit more on this discussion, I'll be speaking at Social Matchbox 4 on Non-Completes. If you live in Virgina, California, or Massachusetts, the courts and legal system take a special perspective on Non-competes…