I've seen a lot of posts concerning non-compete agreements, and the concept that anything you work on belongs to your employer, not you. As someone who likes to tinker, this scares me.

I'm not saying I'm going to create something that becomes the next Facebook, or even the next Bingo Card Creator. I'm unlike most people here in that I'm risk averse (and self-conscious) to the point of being afraid to start my own business, but I do like to tinker. I've had a number of ideas, ones that mostly don't finish because I get enchanted by my next idea and move on too soon, but I do have the goal of publicly releasing things if they ever finish. I just like to play with code.

I worry, after reading certain posts, that just playing with code, and especially releasing things in public, is playing with fire in this industry. I worry about starting anything because I don't want to get a job and have to kill my project because I hate the idea of some other company being able to swoop in and claim my IP. Maybe these sorts of agreements aren't as popular as I've been led to believe, but the idea still scares me.

What finally led to this post was a comment thread on reddit[1], where someone wanted advice about taking a job with PayPal. One piece of advice was to be wary of these sorts of NCAs, and I commented on it, basically stating there what I'm stating now - these sorts of agreements scare me. I got one reply[2] which said (paraphrased), "if you're working outside the job, then you're not fully committed to me". Statements like this make me want to go dig ditches for a living so that I can keep coding as a hobby without fear.

I'm young and naive, so I definitely assume I'm overthinking and overcomplicating this whole deal, but I don't understand why anyone would give up their every thought to a company.

Can someone shed some light on this? Are these agreements common? Why does anyone agree to them? How can I get a job without being worried about writing an answer on StackOverflow and not getting fired/sued for it?

[1] http://www.reddit.com/r/PHP/comments/mwnva/just_got_a_job_offer_out_of_the_blue_from_paypal/

[2] http://www.reddit.com/r/PHP/comments/mwnva/just_got_a_job_offer_out_of_the_blue_from_paypal/c34in7o?context=3