The GPL (and LGPL) require something very simple before even getting to "derived work" and
complicated legal matter: when you distribute [L]GPLed code you must inform the recient and
must either provide them the source or a written offer to provide the source.
They never bothered. Not even after clients explicitly asked them.
Not even after the Busybox authors asked them nicely.
But a call from a lawyer and suddenly they become very nice and cooperative.
The authors of Busybox have tried other methods before:
http://www.busybox.net/shame.html
Anyway, the company is not a "small guy". It is run by "Graham Radstone is a lawyer with over
20 years international business experience. He has held senior positions in some of the
world's leading multinational companies that has included DHL, Philip Morris and Pfizer".
http://www.monsoonmultimedia.com/executives.html