Are the cracks in Sprint’s unlimited data starting to show? With all the other major carriers gone the way of tiered data, it’s been feeling like Sprint’s unlimited smartphone data offerings may be on borrowed time. For now, your data plans are mostly safe, but we’ve learned about the start of what could be a gradual chipping-away at unlimited data, with the carrier confirming plans to start capping data usage shared with other devices via mobile hotspot.

Starting October 2, if you have a smartphone on Sprint and want to do some mobile tethering, you’ll continue to receive unlimited data on your phone itself, but that amount of data you can share over WiFi with your other devices will be capped at 5GB a month. Bandwidth consumption counts both 3G data and 4G WiMAX data towards the same total. Exactly what happens past 5GB hasn’t been officially confirmed by Sprint, but a leaked document suggests it’s considering $0.05/MB overage charges.

If it wasn’t stupid enough to be putting different limitations on data based on where those bytes end up, apparently this new mobile hotspot restriction will only apply to smartphones, and tablet users will continue to enjoy unlimited (4G) wireless tethering. Man, Sprint, you used to be cool. How much longer until on-smartphone data sees these same kind of caps put in place?

Source: BGR, Sprint Feed