Its not a "don't have it" but don't walk around with one and fiddling with it / sniffing / doing replay attacks."
The thing that you don't want to do is go walking down a hallway in a hotel (which are of course under video surveillance) and have a utility room door pop open.
If you have a legitimate use - go for it. If its "I brought mine because I'm going to a hacking convention in Vegas" it is now a "think about if you really want to be carrying it around" - its more likely to borrow trouble and if you "accidentally" open up some place you shouldn't have access to, it makes things worse.
Having them with the intent of drumming up sales, or teaching use, is not a crime (based on the wording of the law you supplied).