In its early days, Apple embedded a couple of no-op string variables, including ...

In its early days, Apple embedded a couple of no-op string variables, including the name of one of its programmers, in the code in the Apple II's ROM. Franklin Computing produced a clone. Apple didn't have to look hard to find its programmer's name in the cloned code. Apple successfully sued for copyright infringement. [1]

[1] http://en.wikipedia.org/wiki/Apple_Computer,_Inc._v._Frankli....