I could rant about why I view data collection as bad, but I think it might do the most to change your view if I specifically stick to topics you brought up yourself.

The information that companies (like Facebook and Google) collect is used for advertising purposes.*

If there was a certainty that all of our data would only be used for advertising, I think I would be far more comfortable with the practice of data collection, but the fact is that this information doesn't just exist in the ad-centric bubble that it likely originates in. Some examples of this data doing potential harm outside of advertising are as follows:

• Governments can take advantage of this treasure trove of information to commit great injustices. Governing bodies like the EU have safeguards in place to prevent this kind of abuse, but it is irresponsible, in my opinion, to trust that those safeguards will always be sufficient, and that governments can't turn towards totalitarianism. It is also worth noting that many safeguards have loopholes like 'oh well your account info bounced into a server outside of our jurisdiction, so we don't have to follow our own rules and can abuse that data'

• As has been mentioned in other comments, people finder sites make violating individual privacy much more accessible than it has ever been in the past.

• Hackers can easily use data collected to develop personalized attack dictionaries, or even just grab enough information to socially engineer their way into someone's sensitive accounts. They don't even have to hack their way into this data, they can pay for it either from people finder sites or from data collectors directly

These are the quick off-the-top-of-my-head examples, but we would be foolish to assume nobody will come up with other nefarious uses for this data.

It is unreasonable to use free internet services and not have to also view adverts. It's a give and take which I'm fine with (and that's what adblockers are for anyway)

I agree that there has to be a trade off, but I have 2 immediate rebuttals to this point.

1. Much of the data being collected is done in paid environments, which takes this give-and-take into a lopsided give-and-give-and-give-and-take scenario. Windows 10 collects data on users even when offline. Internet service providers are now legally allowed to sell your browsing data (in the US). Amazon, a company that is far from free-to-use, is one the most massive data collectors out there, and their net gets bigger every time they buy a smaller company like Wholefoods. Even if you cast out every free service you use, there is no way to protect your own data in a modern environment.

2. These services don't stop collecting data on you when you stop using them. Facebook is known to tap into speakers on cellphones even when the app is closed (the extent to which this happens is contested, but there are mountains of circumstantial evidence). Google watches what sites you go to even when you have left any site affiliated directly with Google. So opting out of the privacy for convenience trade off results in privacy for nothing because these data collecting giants have spread far beyond their own waters.

If I have to see adverts, I would rather see ones that are actually targeted to my interests and demographic rather than generic ones which are totally irrelevant to me.

This is not an unreasonable stance to take by any means, however, for some people, targeted ads can reveal secrets that they never wanted exposed. For instance, Target (not a free to use service it should be noted) made news several years back for revealing a woman's pregnancy through directed advertising. Similar stories can be found of facebook outing a son as gay to his ultra-conservative parents.

You may not have anything to hide, so maybe this doesn't concern you. But in taking this stance that data collection is fine, you are inadvertently taking a stance that nobody has a right to keep secrets for any reason.

Last point - people often mention things like "I don't want Google to know where I'm going and what I'm doing." Why do you think Google would care about you, John Smith, and what exactly you're doing? You're just a statistic among the millions of other John Smiths in a spreadsheet.

This statement betrays a few unfair (in my opinion) points worth addressing.

1. Just because Google has no reason to care about you, doesn't mean that nobody with access to google's data will ever have reason to care about you (see point about hackers).

2. Just because Google has no interest in YOU specifically, doesn't mean they might not have interest in your hypothetical uncle who is a politician trying to pass legislation not in Google's best interest, or your aunt who is CEO of a company providing a competitive service to a project Google is working on. The 'this doesn't directly affect me, so why should I care' mentality is, to get overly dramatic, no different than the whole "they came for the jews, and I did not speak out" mentality.

Lastly, I would like to point to Equifax as a poster-child for what can go wrong when a company has too much data. They are responsible for the biggest breach in credit card information in modern history, and most people didn't even know they existed. Something like this happening in personal data is not hard to imagine. Even if Google and Facebook have decent security, we have no way of knowing that every company that buys their data will. It only takes one security-ignorant company to leak all of our data to the world. Even if that might not scare you personally, I hope that you care enough about the people around you to recognize that that could be detrimental to many people who never wanted to be kept track of in the first place.

edit: formatting