How are you not informed in advance? Every job I've had, there's a contract I sign in advance with all terms, and no addendum on day one. I'd think you could refuse to sign an addendum, and even sue for promissory estoppel if they fire you for not signing.
Yes, a lawsuit aimed at a big corporation will be surely at the fingertips of everyone who is forced by circumstances to sign such clauses.
Let's be real, most people will sign whatever is presented to them on day 1 of their new employment because they need money now. They could refuse to sign, in which case they will be shown the door and encouraged to seek opportunities elsewhere.
That in 4 years time they might've won a legal battle they can't afford is little consolation when they won't be able to make rent now.
Nevermind that once they are in a legal battle, they'll have great difficulty being hired again.
Please don't take offense, but the level of disconnect shown on HN from the prospects and struggles of an average person is sometimes staggering.
