I wasn't asking for the definition of market failure. I was asking what you claim is the market failure
here.
> Facebook have my data, they use it, without my consent and I have no way of taking my business elsewhere to remedy that. This is one of the many costs facebook impose on all of us. These are costs that not all of us feel we want to bare or feel there is a benefit from it. Us stopping using facebook does not fix that cost, we continue to incur it. That meets the textbook definition of "market failure".
I cringed when I read this, because it's an egregious abuse of economic terminology. You're using the term "market failure" as a synonym for "something I don't like". That's not what market failure means. What you're describing is "people have information about me that I wish they didn't have". That's not a market failure. It's like when people misuse the terms "Dunning-Kruger effect" or "not even wrong" without understanding their real meaning.
> Eg it's market failure if I don't like the color my neigbor paints their front door
This confirms my suspicion that you don't understand what market failure means. Stop abusing economic terminology and read up on what Pareto efficiency means. Here's a hint: The scenario you described is perfectly compatible with Pareto efficiency. Market failure implies Pareto inefficiency. Therefore, the situation you described is not a market failure. Seriously, you should make an effort understand the terms you're using (especially technical ones) before throwing them around.