@LukeAlmighty Ah, I understand now.
I thought that he was saying that "the hypothetical that the majority of twitter users would agree with twitter's hiding preferences terrifies me", rather than "the majority of twitter users agree with the hiding preferences, and that terrifies me".
You're right, it makes much more sense this way. And I agree, definitely selection bias.
Expand your thoughts a bit because it's a little too bit dense for me to follow what you meant.