Anecdotally, I've worked in Colorado my entire career (17 years now, over half a dozen jobs) and have never signed an agreement like that, and have never been asked to sign one. I go out of my way to bring it up (in writing, even), because it's a deal breaker for me. Never been a problem.
And logically it doesn't make any sense. GitHub profiles can't be used as resumes if employment contracts prevent everybody from contributing to projects on GitHub.
For me, it's a significant attraction to working for the government - if I'm not in the office what I write is presumptively mine; while I believe at the state level anything I create at work is not public domain, I don't remember any IP agreement beyond the ordinary work-for-hire relationship.
This is 100% untrue. IP assignment is not enforceable if you do work on your own time and use your own equipment (including connectivity).
If you don't own a personal computer and your GitHub page is loaded with commits during your working hours, yeah you're going to have a hard time arguing it's not company IP. But for the vast majority of developers this is a complete non-issue, and insinuating the contrary is just FUD.
Even if there's some question as to the theoretical legal enforceability of an agreement, if you have to sign it to have a job, then it's not practical to challenge it. You'd have to have the resources for litigation as well as to make a living after being blacklisted.
It is true that people ignore their agreements (about IP, not to run a side business, etc) when they think the company will never notice. That's still a meaningful risk that exists that some day they will.
Also, posting bare links as replies is annoying. Please add some context.
“ anything you do on your own is owned by your employer.”
If you use their equipment or their office or their phones. But doing a software project at home on the weekend on your own computer is not going to be owned by the employer in the states I’ve lived and worked in (VA, GA, TN, NC).
Do you have a source for a state where this has happened?
I had an offer from a game company that went through my list of disclosures and said I would have to report my potential book royalties to them (why? Dunno) and that I could not continue to work for the local university. I was dumbfounded. I explained upfront in the interview I worked 5-10 hours for the school and the recruiter said that was great and that my new manager loves giving back. Unfortunately legal did not. I ended up backing out of the offer. I still kinda regret it because it was a stellar team working on neat problems.
All that to say I can see companies asking you to sign something that wouldn’t hold up if you had the means to challenge it. I suspect most people done have the privilege of paying $300-1000 to have their contracts reviewed / red lined.
I mean, I've never had a six-figure job, but I could pay that much to have a contract reviewed, if there was a point. But I don't think there is a point, because unless I literally had a bidding war going on for my services, I'd have zero leverage.
A few years back, I thought I'd figured out how to negotiate, because I tried a method when buying a car that worked very well. But it completely failed when negotiating a salary, because tying someone in knots and exposing their BS, no matter how politely, has no value whatsoever when you don't have an immediate alternative. If you're trying to buy a new car and there are several dealers in town with the same one, that's completely different from having a single job offer outstanding.
I've learned in my personal life too, it doesn't matter how inescapable your logic is, if you don't have any leverage and the other person is willing to jettison logic, it's irrelevant.
As I will keep saying it does not matter if companies follow up on their threat or not. It still has a chilling effect on people doing side projects which is the intended behavior. And a lot of people can't afford a legal battle even if they had a high chance of winning.
Just like you can't necessarily afford to engage in the legal system, the legal system can't be engaged if they don't have a signal that there's anything there to engage with.
And in interviews you can still use the experience and talk about your contributions without releasing the product/ identity to your current employer, and your current company is incredibly unlikely to come chasing after you years later on things with no obvious connection to your real name.
This is the exact opposite of what you should do. As soon as you start working on a side project that doesn't overlap with your day job, you need to tell your company to get it added to your contract's list of excluded projects (meaning they've verified it has nothing to do with them, and you're free to do whatever you want with it).
Issues happen when you leave your job and launch a side project not long after, creating a bit of a surprise. But if you had disclosed it previously, your previous employer is shit-out-of-luck.
And I mean hey, it's working isn't it? Can't show external evidence of your work and skills, now you're a bit more trapped here.
And I am sympathetic: those are completely unreasonable and anti-competitive employment terms, and I've had a past supervisor subtly imply they 'might own the intellectual property of all my thoughts', to which I can only offer the potentially useless advice of don't work there, or do work there but ignore/fight them.
In any state besides California and Illinois you will be forced to sign an IP assignment agreement to work for any medium/large companies. Open source projects will not let you contribute under such an agreement, and anything you do on your own is owned by your employer.