Holy Jesus I accidentally turned on Firefox Sync

Good morning,

Once again I think I’ve made a huge mistake…

I was trying to alter the settings in my Firefox/Mozilla profile and out of the blue it seems like Firefox turned on its syncing service and started syncing literally all of my personal data.

Of course, I’ve turned the sync service off now, but is there anyway to delete this data that was already uploaded to the Mozilla servers?

Does anyone here dare to use the Mozilla sync service? I’m researching it now as to whether my data is safe or not.

Thank you for reading my question!

My understanding is Firefox Sync is it is both E2EE and open source (and from a reputable organization you are already placing trust in) so I wouldn’t worry that much.

That said, general piece of advice since this is your second "holy shit I screwed up"post in a few days, you should be more deliberate and careful about what you do on your system. If you spend a few seconds thinking through your decisions before and a few minutes researching things before enabling them, I think you will have a lot fewer panicked moments like these.

Also as @anon4510900 said, it shouldn’t be possible to accidentally turn on sync nor should it be possible for FIrefox to turn it on without your consent as it requires you to set up an account before you can use it.


I appreciate your replies!

Yes, I know this is the 2nd time I’ve done this and it may be because I’ve been awake late trying to get too many things done in one night.

However, the “Mozilla Sync Service” really did turn itself on and selected all of my personal data: Bookmarks, History were automatically selected.

Here is an image that instantly made me feel intense horror: https://assets-prod.sumo.prod.webservices.mozgcp.net/media/uploads/gallery/images/2021-04-12-15-17-45-ed2347.png


With the default state of Firefox, sync is disabled and there is no Mozilla Account attached to your browser profile. In order for sync to be enabled you’d have to

  1. Create an account
  2. Sign in to the account you created
  3. Enable Sync

I can understand how 2 and 3 could possibly be done accidentally, but 1 would definitely have to have been a deliberate action.

I’ve used Firefox since the early 2000’s and never used sync or needed an account (based on the way I use the Browser, I see the value in Firefox Sync for other people). In any case, I wouldn’t worry, Firefox Sync is privacy-preserving and privacy-respecting from what I’ve read, just disable sync, delete any stored data if any exists, and you should be good to go. Disable your account or sign out if you don’t use/need it.


I appreciate your reply!

I think what happened is that I have a Mozilla/Firefox account for the Mozilla Community Support Forum and I also had a Mozilla account that included everything…

If I delete my Mozilla account I may also delete my mozilla/Firefox account for the Mozilla Community Support Forum and that would suck…

Then don’t delete the account… Mozilla is a reputable organization and your data was e2ee, so there isnt much to worry about imo


That makes more sense.

If you get value from having an account, no need to delete it. Just disable sync and delete your data if you need/want to (idk if it is stored remotely or just synced device to device).


I appreciate your replies!

How can I delete my personal data that was synced to the Mozilla servers??? :sob: :sob: :sob:

The internet could be of use to you: Delete sync data from Firefox by signing out of your Mozilla account | Mozilla Support

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Firefox sync is both open source and E2EE.

I understand a desire to maintain privacy. However, not every convenience equals a privacy risk.


That’s for deleting firefox data from your device, not from mozilla servers.

Maybe this is what the OP is looking for -

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You’re right, my bad. also this might be of interest as well: How do I delete my synced data from Mozilla's servers? | Firefox Support Forum | Mozilla Support

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