This is post #4. I will make post #5 tomorrow.
enigmoid asks, "How do the fae remain hidden from the human world from cameras recording devices, and satellites? It only takes one mistake."
Ah, but you see, there are two assumptions here.
1) That fae illusions do not work on recording devices. They do.
2) That anyone would believe what they saw.
Mistakes have been made in the past, and I mean the recent past, not the old, dark, pre-hiding past. Illusions have slipped, things have been seen that shouldn't have been seen...and you know what? People shrugged it off. For every "I WANT TO BELIEVE!", there are ten "I do not want to live in a world where that is possible, and thus it is not possible." Consider the zombie walks, LARPs, comic book conventions, real-world superheroes, and Bigfoot seekers in our real, known world. Consider how few of those are reported as proof of the supernatural.
Now consider what an excellent source of camouflage they are.
Satellites are a different can of worms, and one with potentially more issues, since if the military spots a pod of Merrow, they're likely to respond...badly. But at the same time, that's where the fae predilection for hanging out in the Summerlands comes in handy. Most fae, if they're not indoors or playing human, are in knowes or the Summerlands. Why? Because they feel safer there, where there are no satellites.
So yes, it's a concern, and a good one. But willful blindness and basic caution do a lot to minimize it.