My biggest problem is with alien abductions and people who see alien beings, because if there truly were advanced intelligent life forms with the technology to travel across the solar system, why would they send fleshy death-prone beings when they could just send microscopic robotic probes or something else along those lines.
According to this book I've been reading:
They indicated that their work was necessary and for the the betterment of mankind-that mankind could destroy itself through pollution.
"The problem apparently involves man-made toxins working their way through the food chain. It has something to do with chemicals and chemical changes. It has to do somehow with nuclear testing or wastes, which are causing a change in certain chemical compounds. Much more is involved than simple pollution.
...the problem has already passed a certain state. It has moved from water to vegetation onto animals. ..the extent of contamination was being determined by studying the reproductive system of animals.
-excerpted from Alien Agenda by Jim Marrs