HACKS:

Looking at the design of the head band, it seems like the camera can still see a person's profile.

More effective of course if a critical mass of people use it. This will block your image on any given camera, but may well make it easier to track you across systems given the unique signature. Trying to hide by drawing attention to yourself may not always be the best strategy.

I have to admit, that's pretty smart! Underhanded, but smart.

Make sure you drive the LEDs continuously and not pulsed or the camera will still catch you, maybe not on every frame, but they will still catch you.

I'm sure there would be harsh penalties for using one on your license plate, or in the commission of a crime.

It's easy to do, but it's also easy to detect and easy to counter. If it really catches on, it would be easy to build a tiny detector that the Police could carry around (no bigger than a button-cell keychain LED light.) If it really catches on, security cameras will start being built with beefed up IR filters; they already have them, but they currently use just enough so normal IR isn't a problem (night-vision cameras would be completely vulnerable, however.)

This is awesome. I might try and build one myself. Security camera's absolutely suck. And in this day and age of advanced spying and tracking of our movements, I'd use this to keep somewhat anonymous.

Build it into a baseball cap with the light in a logo area. Then the battery goes under the cap and you can walk around with 1. the light making a halo, and 2. the bill of the cap will cover your face a tad from above.
So, Where can we buy or build the lamp?