If you are 14 in 2026 and should be picking your clothes off the floor and helping dad with the laundry, thats pretty good return on your data, sold to the ad-men. And, it's probably illegal for them to profit off a kid's online time like this.
Anecdotally I am told placement for high net work goods to prospective buyers are significantly more valuable to a website placing ads, than runescape ads. But, there are far less BMW drivers seeing those HNW ads, than kids seeing runescape so it kind-of evens out. That's probably why on the (now rare) times I am in business class long haul jets, I get told I should be using swiss banking, and invest in property in dubai, rather than being told to buy burgers, which frankly is much more likely to happen.
To make $14k off your facebook time, either you paid some FB coin to do mafia wars, or they shopped you to a lot of ad sellers. If you actually bought anything, especially if it was expensive, then everyone (including you) in the deal might be cool with this.