In practice, I think that's yet to be determined. GDPR is new. These rights are new. "If it's faulty" is easy for lawyers to determine. "Fit for purpose" ...isn't that hard, and the lawyers have had time to practice. "Unnecessary PII collection or processing" ... the lawyers are currently 23 wikipedia links deep^ trying to identify the aristotelian truth of the matter, presumably in order to make necessary amendments to the aforementioned contract.
Shops putting signs on walls is just not comparable to this, in practice. Normal people are signing dozens of pseudo-contracts they don't understand each day. That has been accelerating and gdpr has accelerated it further.
That’s actually a great point. Collecting PII is NOT illegal, as far as I can see. Nor can it be illegal. Same for personalized ads.
Consider a real estate agent. To show you the right kinds of houses to buy and finally make the contract, they have to have enough PII about you. If they know nothing about you, they’ll end up showing 1-bedroom studios for a family of five and a three bedroom suite for a bachelor living alone. Similar arguments can be made for all kinds of service providers.
Now onto the issue of FB, the only service they offer is “communication tools with built in personalized ads”. PII is necesary to provide that service.
I'm also curious where other points will land in reality. eg, if I ask Apple to remove all data they have about me, will that also remove me from your address book? If I ask Google to remove all data they have about me, will that also remove any emails you've received from me?
In this light, I'm happy to see the first complaints arrive against Google and Facebook, as they're exactly the examples we all have in mind, and we need to see how they'll play out in reality.
(Albeit, I also trust the European legal systems won't commonly wield the maximum possible fines, but rather seek compliance. The scary big numbers, the source of so much FUD, should be reserved for wilful disregard after this step. "Walk softly but carry a big stick" style.
Their case will be helped by the fact that they can simply have the user “consent” to stuff. And since none of those are “critical” services, they will find ways to prove that user consent was actually voluntary, and not coerced.
So I think you’re right that only the most egregious violations will have real trouble.
The judges might also want to demonstrate to everybody (including their own system) that the big stick can in fact be wielded to real effect. If people start beliving that the stick is really just a prop, no point carrying it, is there…
Article 6 [0] is phrased negatively, making collecting PII illegal unless x or y. These points cover all the use cases the lawmakers deemed valid; a real-estate agent may collect PII because of 6.1b (taking steps to enter a contract at the request of the data subject). Should a new, possibly valid reason to collect PII come up it would first need to be checked and then added to the list.
Since most websites and online services do not aim to form a contract nor fit points c-f, they have to obtain consent by the data subject (6.1a) to make collecting PII legal.
Many common purposes for data processing might come under point f (legitimate interests) depending on the circumstances. Analytics, marketing, monitoring to check for fraud or other abuses are just a few examples.
If a shop says "no returns", what they actually mean is "changing your mind or deciding you don't like it isn't a valid reason". But you can still return something if it's faulty, isn't as described, or isn't fit for purpose - because they're your legal rights, phooey to the store's return policies.
It's my understanding (which could be wrong, is constantly evolving, and desperately needs test cases) that being able opt out of unnecessary PII collection or processing is a legal right, and phooey to the ToS that claims otherwise.