For mobile this is more likely only because people within the same region (say a small city) are going to bounce between connections much more than a home connection is going to change the IP (IP leases are long for most ISP).Which can kill a lot of other valid users accessing (think of a mobile user). The ONLY time I use an IP ban is when that IP is not an ISP but related back to a dedicated IP in a hosting environment. By banning IP's willy-nilly now, you take to big a chance of limiting access of valid users.
This also assumes that you're going to have multiple users within the same region, using the same ISP/carrier who are going to be visiting your site... And unless you're one of the largest sites out there, it is also very unlikely that this would happen.
The reason to not use IP Banning is just that IP Banning rarely works as you can use Tor, VPN or a free web proxy to bypass a ban.