It's a matter of trust. If you still trust them after something like that,
your trust is easy. Mine is very difficult.
If you believe it was an unintentional bug then I would go so far as to call
you gullible.
A gullible person doesn't test browsers with tcpdump.
As far as the tcpdump test, I just did it and twice. Nothing showed up. Zero
(0). Firefox is pinging nothing, no background connection whatsoever.
Please share the STR like I did, so we can all look further.
Now, I do need to make it clear that I am one of those guys that prefer
spending 50 hours of their time if need be in order to make it right.
Me too. But I hope you would agree that the very fact that those 50 hours are
needed is a proof of bad design.
You can see the connections it makes in about:networking too.
I wouldn't trust that. I would rather inspect with a separate tool, not made
by the same software vendor (tcpdump, wireshark).