Microsoft has confirmed that there's an issue with its built-in Twitter feature that could result in unexpected data usage. The issue stems from a Twitter back-end change that has caused Windows Phones to re-download the profile images for Twitter contacts frequently. Twitter is currently transitioning its profile pictures from one server to another, and The Verge discovered the data use problem nearly a week ago and reported it to the software giant.
On one of our own Windows Phone devices we found that the People hub, the section that hosts the built-in Twitter client, had used over 300MB of mobile data and over 3GB of Wi-Fi data in just under a week. The data drain occurs even if you don't use the People hub. It's not clear exactly when the issue started, but the level of data use will depend on how many Twitter contacts Windows Phone users have listed in the People hub. Verge readers have confirmed the issue on a variety of handsets, and we understand it's not related to any specific Windows Phone update so any device could experience the problem. Some readers have reported 530MB of data use for the People hub in the last 30 days, and others have seen 412MB of data use. If you're on a 512MB or 1GB monthly limit, then that's a significant problem.
Microsoft has a temporary fix in place
Microsoft is working to address the issue, but as it's a backend Twitter change the company is limited in how it can best address it. Removing a Twitter account from a Windows Phone will prevent the excessive data use fully until Twitter has completed its server migration in the coming weeks. Microsoft has also implemented a change to only sync Twitter accounts once a day to reduce the impact. If you're worried about excessive data use then you can check the Data Sense application in Windows Phone providing you have enabled the feature. Otherwise, it might be worth checking with your mobile operator to ensure you've not passed your data limit for the month.
Update: Microsoft has confirmed, on November 10th, that the temporary issue is now resolved.