As far as I know, the simple metallically-coated anti-static plastic bag that's provided with EZPass (and similar electronic toll systems) is quite effective and very cheap. Aluminum foil will also do in a pinch. On Aug 7, 2013, at 2:01 PM, Scott Kitterman <scott@xxxxxxxxxxxxx> wrote: > On Wednesday, August 07, 2013 13:43:06 Joe Abley wrote: >> On 2013-08-07, at 13:28, Ted Lemon <Ted.Lemon@xxxxxxxxxxx> wrote: >>> [...] I don't think you can argue that carrying an RFID tag with a simple >>> number in it makes things any worse. >> That sounds right. >> >> The purpose of the badge is to dilute your personal privacy and announce >> your identity to those close enough to see. You can't always tell who is >> looking at your badge. People who see your badge in more than one place can >> infer that you have moved between places. If you don't want people to see >> your badge, you can take it off. > > In RFID terms, that's what the Faraday cage is for. > >> The privacy concerns with badges seem very similar to the privacy concerns >> of carrying RFID tags. >> >> I do not hear a lot of expressed concern about wearing a badge. > > It's more common to have a pocket available than a Faraday cage. > > Scott K > >