It was only five days ago that I predicted Sprint would have to put an end to its unlimited data plan, and it seems that I was right. Following Verizon and AT&T’s lead, a leaked internal document reveals that Sprint will start capping their unlimited tethering data plan to 5GB/month, starting October 2nd.

In views of all the recent hints that Sprint will get the iPhone, this move was most likely made to prevent future iPhone users from going over the top with data while using their device as a mobile hotspot…

All smartphones on Sprint will keep their unlimited data plans, though. The only difference is that they won’t be able to use the $30/month tethering add-on for more than 5GB/month. So technically, it’s still unlimited data, you’ll just be capped at 5GB. Once you reach those 5GB, Sprint will charge you an additional $0.05/MB.

Should Sprint get the iPhone next month, I assume that they will eventually drop their unlimited data plans all together within the next few months. But first, they’ll make sure to reel in as many new iPhone users as possible, just like Verizon did when they first got the iPhone.

[SprintFeed]