AT&T is apparently cracking the whip when it comes to popular MVNO Net10. The company has announced on its site that new AT&T data caps went into effect on March 1. From here on out, all AT&T SIMs on Net10 will be limited to 1.5GB of high-speed data on the "unlimited" plan. If you want more bytes, a T-Mobile SIM is your only option.
Net10 has always been a bit vague about how much data you can go through before hitting the soft cap.