You should probably check it, in the UK this is pretty standard, and I believe it is in the US as well. I suspect most of Europe is similar as well. It will vary by company and industry, but in my experience when you ask HR and Legal to put together a contract for a knowledge-worker, this is a standard edition by them.
I've never had a job actually assert anything around this personally, but I do make sure to have anything notable signed off by my employer as "mine". That's assuming it's unrelated to my employers field of course.
Yeah I always check this too - and if needed add a clause to my contract to make it clear that programming work I do outside of business hours & using my own equipment remains mine. I do a lot of opensource work and it would be a disaster to have copyright ownership clouds hanging overhead.
But for a company to assert a copyright like this, they would have to actually sue. And companies will always be loathe to sue employees over incidental stuff like this because the negative press will almost always make it not worth it.
They agree with you that your company does not want to sue. Specifically (in some cases) they explicitly remove your ability to sue violators.
Obviously each company and employee situation is different, but the default position is they own the copyright, and they'd prefer not to sue anyone.
This leads to copyright violations being ignored.
Whether violations are something you care about or not is up to you. Personally I don't get over wound up by it (my code is pirated all the time) but others feel very strongly in this space. This article is pointing out that if you do care, then it pays to make sure where your copyright exists.
I've never had a job actually assert anything around this personally, but I do make sure to have anything notable signed off by my employer as "mine". That's assuming it's unrelated to my employers field of course.