Alternative types are often the most conformist, despite their appearance. Not all are of course, but I suspect most people will waive their right to privacy in this case.
I imagine Glastonbury would face more of a backlash due to it's size and the fact it's sold as being a bit alternative and hippy (despite the fact it isn't any more). Reading and Leeds might go for it, depends on what sort of backlash they got on Tw*tter or F*cebook.
Currently as I type, the tw*tter stream is filled fill starving Download punters as their RFID payment system isn't working. So I guess it's sorted itself out.