Sometimes when a cloud service makes a back-end change it breaks an app, but at least it doesn't break your bank. Not so for Windows Phone, as some users are reporting increased data usage linked to a server migration currently underway at Twitter.
The migration, as reported by The Verge, is causing the built-in Twitter functionality for Windows Phone's People hub to download Twitter profile images several times a day. The issue is not affecting all Windows Phone users, so your mileage may vary.
At its worst, users are reporting around 400 to 500MB of wireless data usage over wireless, with one user reporting usage as high as 530MB. The Verge said one of its Windows Phone devices used more than 300MB of cellular data and a whopping 3GB over Wi-Fi in just one week.
Any Windows Phone users with limited data caps of 1GB or less would be well advised to make sure this problem hasn't pushed you over the usage limit for the month.
To help ease any issues, Microsoft is reportedly only syncing Twitter accounts on the People Hub once a day.
This isn't the first time that mystery data issues have hit the Windows Phone platform. In late 2010 and early 2011, Windows Phone 7 users reported their handsets were uploading about 50MB of mysterious data every day. Some phones were sending the data over a 3G connection even when connected to Wi-Fi. That's not a lot of data, but nobody likes a mystery data upload emanating from their phones.
Microsoft later blamed the problem on a "third-party solution commonly accessed from Windows Phones," according to Seattle PI.
For Windows Phone 8 users experiencing the current problem, it seems your best course of action may be to delete your Twitter account from the People Hub for now. The server migration will reportedly be ongoing for several weeks. The good news, though: You can still use Twitter's own Windows Phone app instead of having tweets plug up your People Hub in the first place.