"require intermediaries to pass on notices of alleged infringement to their users" aka they can intimidate and mislead gullible users into paying penalties for copyright infringement even if they aren't legally required to.
As someone outside the US, this trade agreement seems like the US trying to impose its poisonous, backwards copyright and intellectual rights laws on the rest of the Western English speaking countries.
All behind closed doors of course, with no open debate, to the massive boon of greedy corporations and at the expense of the common man as per usual.