We’ve written about Virgin Mobile’s pay-as-you-go cell modem offerings before, so this development may be of interest to The Loop readers: Virgin Mobile has indicated that it will throttle its heretofore “unlimited” data plan for its Broadband2Go devices.

[ad#Google Adsense 300×250 in story]Virgin Mobile offers an affordable alternative for users looking for occasional wireless broadband access on their mobile devices. The company offers a Mac-compatible USB-based device and a MiFi device that are available without any monthly contract; users instead opt for a two-tiered pay as you go strategy: $10 nets you 100MB of bandwidth which must be used within 10 days, or $40 gets you an unlimited plan that works for 30 days. After the time is over, you pay again to continue to use the service.

This proves handiest for occasional mobile travelers who don’t use their devices constantly, but may need them from time to time. There’s no penalty incurred for simply having the device on hand, and you can use it as mobile data access is required.

According to PCMag.com, Virgin Mobile is changing the terms of their $40 “unlimited” plan to 5GB per month instead. After users hit the 5GB wall, speeds are “choked down for the rest of the month,” according to reporter Sascha Segan.

For many users, this won’t be an issue – 5GB in 30 days is a significant amount of bandwidth to use over a 3G data connection, especially if you’re breaking it up with access over Wi-Fi at home or in the office. But if you’re using your Virgin Mobile device to access videos online or if you’re a heavy user, this will impose some potential restrictions on your use.

Virgin Mobile says the new terms go into effect on February 15. So eat up the unlimited bandwidth while you can, because after that, it’ll cost ya.