The comprehensive solution to this issue (as we, the researchers mentioned in the article, see it) should be a combination of API safeguards and to have a hardwired "recording" light on Glass.

The API checks would prevent what we were able to do in Malnotes, and the "recording" light would work much like webcams currently do.

A more technical discussion of what we were able to exploit is on Ars Technica in the comments (skip past the trolls). http://arstechnica.com/security/2014/03/google-glass-spyware...