Ads and the spying they depend on only trick you into thinking that you aren't paying for it when in reality, not only are you paying (often resulting with money coming out of your pocket) but you also never get to stop paying for it.

Once your data is out there, it will be used against you for the rest of your life. It never goes away.

It'll be passed around to advertisers, data brokers, law enforcement, lawyers, employers, insurance companies, scammers, retailers, and activists and year after year, decade after decade, every single person who gets their hands on your data will try to use it against you in any and every way that they feel will be to their benefit, and it will almost always be at your expense.