The book is about some campers in Montana that are kidnapped by the 'horde' aliens. Due to them underestimating the humans, they not only lose their ship, but are teleported into space when one talks to the open computer.
The humans then start gathering people tired of their treatment on earth, and veterans, and start building a moon base. When the government finds out the are rather unable to control the situation, and a fleet of horde ships arrives. They are mostly destroyed and the news of a war starts. It seems the humans have been used in the past to make cyborgs to fight for one side.
This is part of a three book series, and dang if I cannot find the title to reread them.