User Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.102 Safari/537.36 Steps to reproduce: Woke up to a text from T-Mobile alerting me that I was reaching my 5GB monthly data limit. I saw that Firefox had used 3.7 GB of mobile data. I force quit Firefox. This is Firefox version 46.0.1 on a Moto X (2013) running Android 5.1 Actual results: Looking at history, the page I had open most recently does have a (continuously playing?) video: http://www.cnn.com/2016/05/16/politics/donald-trump-cameron-khan/index.html So maybe it was allowed to continue streaming in the background?

The add-ons I had installed were: - uBlock Origin 1.7.0 - OpenH264 video codec (the default as installed with Firefox) 1.5.3

It does look like CNN video uses up a lot of bandwidth. I have had a window open for 18 min and it used 62.5 MB. This translates to ~200 MB an hour and 1600 MB over 8 hours.

Talked about this in triage. This page is pathological. It keeps providing new videos to play infinitely and auto playing them. We have two conflicting asks. Keep data usage low and allow users to play media in the background. Setting media.autoplay.enabled to false in about:config would stop this page from being bad. However it is not a good general solution to the problem as this would break sites. Snorp mentioned that the Taipei team is adding media controls in bug 1268368 which would provide a larger clue that Firefox is doing something in the background.

Bug 1268368 is intended to let user easily know there is media content playing (showing on notification bar and lock screen) and easily pause it. And we plan to stop decoding video and keep decoding audio when video cannot be seen, like bug 1274421 to save power and mobile data.

Thanks for taking a look at this bug -- I really appreciate it. Showing a notification when this is happening probably would have saved me in this case, so I'm happy that's being considered. I realize you have more UX issues to consider than I'm aware of, but if I could make a suggestion: How about also asking confirmation that the user wants to continue streaming media in the background the first time it happens? I know I don't represent all users, but I'd prefer that media stop playing when FF is not in the foreground.

(In reply to imasterson from comment #5) > Thanks for taking a look at this bug -- I really appreciate it. Showing a > notification when this is happening probably would have saved me in this > case, so I'm happy that's being considered. fwiw, having a notification when an app is running a user-observable operation in the background (e.g. music) is Android convention.

It sounds like the media controls are the right solution here, and hopefully that should land soon.

Firefox v 48.0 for Android. Only one window was open: www.alternet.org/election-2016/trump-self-sabotage-campaign%3Fsrc%3Dnewsletter1061977 Firefox was not running in the foreground at the time and I was asleep, doing nothing with the phone. Motorola Droid Mini, system v 24.21.7.obakem_verizon.Verizon.en.US, Android v 4.4.4, Android security patch level 2016-04-01. No other apps were running in the foreground. Background operations might have included Kaspersky Internet Security and Garmin Connect as well as the usual Android suspects. Firefox used 5 GB data overnight. Cost me $75.00 in overage charges. Plus texts from my carrier at 3 AM and 5 AM ... should've roused myself well enough at 3 to turn the phone off rather than trying to go back to sleep ...

I looked at http://www.alternet.org/election-2016/trump-self-sabotage-campaign?src=newsletter1061977 . Chrome gets the same behavior. The page keeps loading ad network stuff. After about 10 min the Firefox devtools show 125 MB of data transfer. This is a website bug.

To keep this from being catch all bug I am going to lock this to editbug users. Bugs are most useful when they deal with a specific instance of a problem. If you have come to this bug because of data usage please file a new bug using this template https://bugzilla.mozilla.org/enter_bug.cgi?product=Firefox%20for%20Android&component=General&blocked=1253346 with your best recollection of what you did (what sites were open) before this occurred.

(In reply to Kevin Brosnan [:kbrosnan] from comment #9) > I looked at > http://www.alternet.org/election-2016/trump-self-sabotage- > campaign?src=newsletter1061977 . Chrome gets the same behavior. The page > keeps loading ad network stuff. After about 10 min the Firefox devtools show > 125 MB of data transfer. This is a website bug. For what it's worth, this behavior could be fixed with bug 1278277 (create a setting to restrict network usage while the app is backgrounded) or bug 1024599 (notify a user if more than X amount of data is used while backgrounded). I also sent a message to alternet about the issue.

We have completed our launch of our new Firefox on Android. The development of the new versions use GitHub for issue tracking. If the bug report still reproduces in a current version of [Firefox on Android nightly](https://play.google.com/store/apps/details?id=org.mozilla.fenix) an issue can be reported at the [Fenix GitHub project](https://github.com/mozilla-mobile/fenix/). If you want to discuss your report please use [Mozilla's chat](https://wiki.mozilla.org/Matrix#Connect_to_Matrix) server https://chat.mozilla.org and join the [#fenix](https://chat.mozilla.org/#/room/#fenix:mozilla.org) channel.