The answer to the question: ...is yes! Ask a someone in NY or NJ what pops into their mind when they see an abandoned backpack in the back of a subway car. The fact is that backpacks, even before their connection with terrorism, have been scrutinized in most major cities for quite awhile. First with the link to potential shoplifting (I remember stores in the early 80s requiring you to check them at the counter), and now with terrorism. The backpacks potential association with bombs, is the main reason backpacks (and virtually every other type of bag) are prohibited from all NFL games: http://www.nfl.com/qs/allclear/index.jsp Naturally, after the Boston Marathon bombings backpacks were (rightly so) put under even more scrutiny: http://www.wcvb.com/article/boston-marathon-deaths-prompt-review-of-security-policy/8180973 https://www.dnainfo.com/new-york/20130426/new-york-city/backpacks-banned-for-five-boro-bike-tour-riders-after-boston-bombings I'm in Philly. Pope Francis came to visit in 2015. Guess what was banned from being carried for blocks and blocks anywhere near where he was going to be? Backpacks...and virtually everything else. http://6abc.com/religion/prohibited-items-on-ben-franklin-parkway-during-papal-visit/968390/ Agree or disagree, there are valid reasons that backpacks are so heavily scrutinized and prohibited in so many places where there is an increased risk for terrorism.