Wait a minute. Why does the Debian-rebranded Firefox go beyond just changing
the software name (the name used to identify the software to humans, relevant
to the Mozilla licensing issue) and also change the _technical_ behavior,
reducing compatibility?
Does the Mozilla license really require Debian to change the user
agent string?
If it really does, could the string be structured something like
"Iceweasel (Firefox compatible)" so that at least some user-agent sniffing
will recognize Iceweasel as the Firefox browser the web site already knows?