I don't see anywhere that they are claiming their business is for copyright infringement, in fact, it doesn't seem like it's for mass distribution at all unless you give out your key, and then you just defeat the point of the service.
It doesn't really matter what you or I think anyway. If it came down to being sued by a copyright holder, a blog post like this is definitely not going to help their case.
Sharing copyrighted material is not a crime unless is an illicit sharing, that is, when you do not hold a license that allows you to do so. So there are many exceptions such as: when you download a song that explicitly allow copies for any of your own devices; the same applies when you are the copyright holder, or when the license does not cover the country where you live.
[0] I am not saying it is good or bad, right or wrong.
[1] Observing, not judging.