There was a story not too long ago where several young people died (listeria?) traced to a re-usable bag.
Here is a paper on the subject:
http://www.utexas.edu/law/colloquium/papers-public/2012-2013/10-01-12_Grocery%20Bag%20Bans%20and%20Foodborne%20Illness.pdf
Thanks for that link!