Nobody that entered the arena signed a contract. You wanna claim that show me one.
If I was one of the reporters I would have run my wifi hotspot from inside a pocket or backpack.
There is simply no reasonable way you can enforce a restriction like this without jamming wifi hotspots. You'd need a ton of gear and a bunch of trained people to find the people running hotspots (triangulating this down to a single person in a group of a hundred people using wifi would be a serious pain in the ass) and eject them and I don't' think for a minute they had this gear. I fully believe they turned on the jamming feature in their routers just like the hotels and then forced everyone to buy wifi access. Though they might have the property rights to eject people for using hotspots (this is not a settled issue, no one can regulate the airwaves except for the FCC and this is certainly regulating the use of wifi), they certainly didn't have the power to enforce such a ban without jammers.
I hope to god if they were using Jammers they hit them with a $750K fine like they did the last Hotel that was caught using jammers.