[pabs3]

> Finding the copyright notices buried ...

The GPL and BSD notices are usually in the same place, in the Settings -> About -> Legal notices dialog or similar.

> Also, who will dig and find that I have used a specific library if I conveniently forgot to add its copyright line to this already long wall of text?

People will still find out. The router I have violates both the BSD license, and the GPL. It simply has no copyright notices at all. The only indication it violates both is the web server 404 page links to the micro_httpd homepage, and the network filesystem feature uses the word samba. Thats probably more common than deliberately incomplete copyright notices. Even more common is wilful deliberate GPL violations.