I'm a PhD student looking at software watermarking techniques and I always get asked 'who uses it?' The answer to which I don't know. There is a large amount of academic work on the subject (most notably from Collberg et al.) but very little indication of it's prevalence in industry. Software watermarking involves embedding a unique identifier into software in order to prove ownership, in a similar way to that of multimedia watermarking. So, maybe programmers here can answer the question: 'who uses software watermarking?'
Thats a very interesting question. I would have up-voted you if I got the permission;-).
I actually wonderred the same question 4 years ago when I was doing my masters on dynamic software watermarks. I heard from some sources that IBM once won a law suit on copyright cases against some company, where software watermark actually got used as a hard evidence. But saidly its merely a heresay as I cannot find any source for that story.
Another case is that a chinese company successfully proved that google china stole their dict data and used in google's chinese PinYin input system. See this
I dont really have an answer to your question. But I believe software watermarks will be recogised as a powerful tool not only in the acdemic world. The reason is with the burst of app store iphone/ipad/android applications, there is real money,lots of money involved in the piracy--anti-piracy battle.
There have been so many cases that people simply download paid apps and reverse engineer them,make minor modifications and then claim copyright and release the apps to make money.
So I will bet a company will be there that speciallises in utilising software watermarks to prove owership, might combind with using obfuscation to make reverser engineering harder.
The market is huge, the problem is getting bigger and the solution has been established (at least in acdemic world) ;-)
It might be time for me to re-read my paper and see what I can do to make some money ;-).