You would be surprised.
A couple years back I used to use Opera Mini to log in on the Temp when I was on the go, I didn't have a proper smart phone at the time so this was really my only option and it worked well enough. One time it just stopped working - it kept maintaining that my IP is banned, but it couldn't have been, I haven't done anything and I could log in to my account just fine from my desktop and the desktops at university. I took the matter to the higher-ups at the time, we had a colourful conversation about the issue, they went through the trouble of checking the banned IP ranges of my entire mobile network and the results were negative - nothing was banned. In the end I mentioned that I was using Opera Mini -
"Oh, that browser uses its own Opera-powered proxy, that's banned." "Why?" "Don't remember. Must've been some spammer, so we banned the whole range. It's cool now, you can log on.". That was a while back, oh yes!
So yeah. Not only can you ban dynamic IP's by
banning the whole IP range, you can ban whole browsers if they use proxies of their own.
;O;