MSNBC aired a report on a class action lawsuit filed against AT&T, alleging that the carrier has been overcharging millions of subscribers. In data comparisons and tests, it was found that AT&T "systematically overstated the amount of data used on virtually every transaction." iPhone and iPad users, a key customerbase, were regularly overcharged seven to 14 percent for data, and were even sometimes overbilled as much as 300 percent.

The excess fees aren't huge, maybe $10-15 per user monthly, but when you're talking about regular overages across an entire userbase, that adds up to a lot.

AT&T says there's no merit to these allegations, and it's sticking to that — even in the face of "phantom" fees. (As a test, a new iPhone's software was disabled, so no data-using applications were running, and it still managed to rack up 35 charges.) The company blames application multitasking and auto-updating software for that, but says most of its users don't incur extra charges.

Visit msnbc.com for breaking news, world news, and news about the economy

While this goes on, you can keep that bill from getting worse. So if you're getting pounded by data fees, check out these hits from the "common sense can go a long way" playbook:

  • Use Wi-Fi whenever you can.
  • Check your data usage periodically. Pop in online, on your device, via the myAT&T app, or just text *DATA# from your phone.
  • Reevaluate your fetch and push rules. Turn off notifications on things you don't need.
  • YouTube and other vid streaming services are big data hogs, so don't watch them on 3G unless it's absolutely necessary. And definitely don't do it if you're in a lousy coverage area. You might get some content dribbling out, as your phone struggles for signal – which will drain your battery too — but what little you'll see will look terrible, forcing you to rewatch it when you have Wifi anyway. So why waste the data?
  • Put your phone on data blackout periods — like when you're traveling abroad. Nothing says "Surprise!" like racking up big international roaming fees.
  • Don't forget you've probably got some cool offline content too. So if you often need to kill time while out on the go, instead of listening to Pandora or streaming clips, be sure to keep a stash of songs, eBooks and other stuff stored locally.

Are you getting hammered by data fees or, as AT&T says, are you staying under your data cap just fine? Let us know if this lawsuit surprises you, or if you have any data-saving tips of your own to share.

[via MSNBC]