Today I was playing the Weekend Warfare mode "Snipers Only" on the PS4, Two idiots came into the server and started killing people with M16's, AK47's, and LMG's.
Yet everything but sniper rilfes are blocked, yet they managed to do this everytime. So I can only guess they are hacking.
I took video of it and I will post it, Their names are Its_Powerz_ and Z-drxft
They are not hacking, there is a glitch you can use to get unlimited selection when classes are restricted. It's not well known, but it exists.