This is why some data protection and privacy laws are starting to require active, informed consent before taking some actions, instead of merely specifying "consent".

Even without that, basic contract law in many places requires a degree of mutual understanding for the contract to be valid in the first place. You can't just bury a surprising term with a huge effect deep inside a long legalese document and expect it to actually stand up in court, and if you're doing something dubious and relying on that as your defence then you might be in for some disappointment.