[bmj]

My experience is that many, many contracts for programmer-types include a clause about intellectual property. In my direct experience, no employer has ever collected on this. I suspect if an employer did exercise it, it would be for IP directly related to their business/product. But...that's a hope, not necessarily a reality.

[eternalban]

My last employer actually said something along the same thing during negotiations. I countered with "then why even have it in the contract?". He was a reasonable man.

Also that whole "related to their business" is over-reach as well. If I work for (say) a database company and am providing quality work but spend my nights at home designing a new kind of database, what possible (reasonable) claim can the employer have on my private work? All this and yet we are "employed at will".