I watched it, amd so far find it an interesting update on the original mini-series. However, as a sci-fi geek, I had a few nits to pick:
1. David Icke has already done this story. Oh, wait, he is trying to sell it as the truth.
2. Every physicist, astrophysicists, engineer and many sci-fi geeks would have been screaming wait a minute if aliens said they came here for elements commonly available on Earth. If it is commonly available here, it is commonly available on other spots in the solar system (without dealing with dangerous sentients like humans).
3. If they want to wipe out humanity, they could easily do it without subterfuge and from orbit.