I noticed for a while using the app TrackerControl that Firefox connects to Facebook sites very often while I surf the web, for example a simple search on Google, or a search on Startpage.com which sites don't have anything in their pages linked to facebook sites.
I have set TC to block trackers in Firefox by default.
Trying to find out when this occurs
I thinked that this happens in general until now. In fact before writing this question I did some tests and I noticed one probable behaviour causing connections every time, that is if I search a string through a Firefox's search engine in search bar. This happens both with predefined engine (google) and with custom one (startpage). This tests was done when I've just opened Firefox in private browsing so that there wasn't other working tabs (and there was no loaded facebook tabs opened in normal browsing tabs).
Here is TrackerControl after a Startpage search (from bar) where Facebook domains result blocked 5 seconds ago:
Here after a Google search (from bar) where Facebook's domains result also blocked 5 seconds ago:
probably (as I remember) instagram's domains are there because I visited it once and it wasn't blocked yet. The relevants domains here maybe are:
The domains contacted are probably all that appear in the screen under Facebook (see 2nd update).
But I noticed just sometimes that connections happen also if I only interact with firefox's bar and digit something. Than if I just use a page like this and I don't touch search bar, connections to facebook seems to not occurs since TC indicates that some minutes passed after the last connection. But now after about 30 minutes another connection was made even if I didn't touch search bar.
Who is the actor
This behaviour is strange and it seems probably is acted by Firefox itself, but it should not. I've never heard or read that Firefox communicates with Facebook and there is no reason, but only with Google for scanning URLs and downloads. Also after searching there are no results. I don't have strange extensions. Moreover I have the ext. μBlock and Noscript that should block facebook together because I explicitly set the first to block Meta's websites in general and the second to block other non website's scripts by default. So those connections in TC should have never occured I suppose except if they are made by Firefox, at which level every extension can't operate. Read 1st update.
The problem occured for months, but I postponed this question until now. This means that I noticed this also with older versions of Firefox before the present since more or less one year ago.
Note: TrackerControl app says explicitly that it doesn't support blocking trackers in browsers yet, but I understood I could use it anyway.
My complete "configuration":
- Firefox from Play Store, version 114.2.0 (same behaviour in newer versions to 119.1.1)
- Extensions: uBlock Origin, NoScript, Decentraleyes, Google search fixer, and other non relevant here but installed noramally from Firefox
- I have search suggestions disabled so no contact should there be while texting in bar. Moreover I have studies disabled and just "technical data and usage" enabled.
- TrackerControl app installed from F-Droid, version 2023.01.31-fdroid
- Android version 8.0.0 (I don't think is relevant)
I'm not an expert of TrackerControl. I hope that someone know what is the reason because is not a good thing. Does Firefox do this in its code or is just an error of TrackerControl (I don't think)? If it's a tracker seems too invasive. Has someone experienced this or can reproduce this? Thanks in advance.
- As asked in comments, disabling all extensions and restarting Firefox (also rebooting Android) doesn't eliminate the problem, connection persists after a search on the bar.
- I tried app NoRoot Firewall in place of TC (both are VPN based); it gived connections to facebook (and also to instagram) in log right after a search. But Firefox connections was all allowed in rules of NoRoot Firewall. After I re-enabled TC (disabled NoRoot F.), which blocked facebook, those connections was more sporadic or absent for some time. But after one day of use (always with TC block activated) the problem returned as before, so the browser tries to connect at least after every search in bar.
- I want to note that those facebook domains which I look often are marked "Essential" by TC. There are some other Facebook domains under "Social networks" which seems also to be tried to connect to after a search.