John said:
For some strange reason, whenever Firefox is open and after visiting
ordinary websites (like ESPN), Firefox continuously uploads data.
This last time, it was stuck at almost three kilobytes per second.
I'm sure it's nothing, but it's troublesome.
Modern versions of Firefox, can be seen placing a message near the
bottom of the browser window, indicating they may send info back
to Mozilla, about browser performance.
But really, if you have any doubts about what it is doing (like,
a plugin is doing this, and not the browser), use Wireshark to log
where it is going. There is no guarantee you can figure out who
owns the IP address, but it's better than nothing at all as a
readout.
(Picture of wireshark, a packet sniffer...)
http://en.wikipedia.org/wiki/Wireshark
When using that tool, go to View : Name Resolution, and
tick all three boxes. That helps get readable names used
for the IPs involved.
Paul