I am afraid there's nothing people can do about this issue: according to https://github.com/osxfuse/osxfuse/blob/master/LICENSE.txt the project is BSD licensed and AFAIK closing the sources of a BSD-licensed project ("re-licensing") is allowed. Yep, he's allowed to do this and people basically have to suck it up. This couldn't have happened if the code was GPL-licensed. This might be a good occasion take a moment to…
Cursory look at recent checkins seems to indicate that he wrote all the code. As the copyright holder of the code he could re-license it the same way even if it was GPL.
1. There are github commits not by him in the project.
2. There are lots of copyright assertions scattered through the project. The first one I ran into was:
> Copyright (c) 2006-2008 Amit Singh/Google Inc.
but I'm sure there are way more than that.