A program that rocked the World in 1998 (or something, the web page I use as the reference¹ forgot to add the year and my memory has failed me.)
It was basically a chain letter, but the idea of it was the distribution of keys; your copy of Mega$Nets program couldn't generate keys if all codes had not been bought. This, however, didn't make it any more legal in most parts of the world...
The program advertised itself as being cracker-proof, it'd use encryption, it'd lock itself if codes were tampered with, some k3wL d00dz had apparently tried to crack it and failed...
...yet a random casual luser could decompile the program in matter of moments to original form (it was written in Visual Basic, see). No need to summon Bruce Schneier or Jon Johansen. It turned out (no surprise here) that the program was crappily written (as someone stated, the programmer was either really bad or really drunk) and it could be made to "cheat" very easily. When people started to "disturb the businesses of the offenders", the program soon went out of commission.
¹ http://ga.to/mmf/meganets/