Actually not wholly true.
You are not giving any consent. A person may film you, but should they wish to share that video commercially or just on the Internet (you tube) or such then they are meant to obtain consent from people in the video. Should they not do so anyone captured or used in the video can ask for it to be taken down, removed or if it was a commercial video (someone made money off it) then reimbursed/compensated for their appearance on it.
Security camera's do not apply as the contents aren't used except to track down criminals and then only the footage of the crime is ever used, and if bystanders are caught at same time their likenesses are blurred out / digitally distorted before that footage is ever shown publicly.
So what you are saying is, if a security camera catches a customer doing something stupid, it can't wind up on the internet without that customer's consent. Legally, that is probably 100% true... however obviously this type of thing happens all the time. There are frequently lawsuits regarding security videos being unleashed. So whether you are an employee at a 7-11, or a dude wearing Glass, you can easily take video you record and then place it online. I'm not saying it's right, I'm just saying that Glass doesn't really pose any new threat we haven't been seeing for years now.
Bottom line is, I think that Glass is way more conspicuous than a cell phone or even a real camera. If I see someone wearing those things, I'm going to know what they are and assume I'm on camera.