(In)secure access code

[bunsen_h]

Should I be concerned that the 15-digit "secure access code" in the 2011 census envelope can easily be read without opening the envelope, by shining a bright light through it from behind?  Thus enabling someone to complete the census on-line for the specified address without leaving any traces other than, say, the IP address from some public-access site..?
 

Comments

[dewline.livejournal.com]

Bad enough they ditched the long form census on grounds that are...debatable at best. But trying to train us to ditch the short form on paper for this?