Hoverboards do exist right now. They just aren't useful or developed well enough to be a mainstream item available to the general public.
Teleportation has been used to transfer data although it's not human teleportation it's well on it's way. And it's very possible it's already happened there is no way for us to know.
And as for the Memory-erasing technology, I stick with my 'even if we did know, they'd just use it on us' theory.
I also think this survey has ****ed up on their wording of the question like a few others have already stated in this thread.
They're asking for peopls opinions i.e. 'Do you think ______ is real?' 'Do you think ______ is possible?' and when the viewer gives his opinion they spin it to make it look like they're retarded and think space age tech exists in it's highest form right now.