About twenty years ago, I was consulting for a large bank that, among other things, was the master trustee for some of the largest pension funds in America. I was part of a team working on a PC-based application that would get data from the bank's mainframe and allow the customers, at their site, to run an analysis on the current data.

My first assignment was to evaluate several hardware and software packages that would do the job of getting the data from the mainframe. I couldn't find anything that worked as promised, so I asked if I could build them something that would. They said to give it a try.

In the end, I built both the PC part and the mainframe part of the link. This was all very new back then, and it took a certain amount of trickery to fool the mainframe into sending the large packets of data that we needed to gain efficiency in data transfer. I also wrote them a scripting language for logging on to the mainframe and a very simple interface for the other programmers to use to request the files they wanted.

The next thing they asked me to look at were some copy protection methods they were thinking of using to make sure that all the users were using legal copies of the software and not copies. I looked at it for a few days, then asked the boss if he really wanted to use this approach. The customer might just want to make a backup copy and, I reminded him, some of the customers had as much as $75 billion dollars in their accounts, so they might get insulted as being treated like criminals. They asked me to come up with another approach.

I came up with a simple method of detecting the use of a duplicate copy. It used a log on the mainframe showing each use of the system by each user as well as the copy information. By studying the log we could detect duplicate copies in use without alerting the user. As a bonus, we could study how each customer was actually using the system.

Finally, my boss asked what we should do if we detected a duplicate copy. Simple, I said. Turn it over to the marketing people and let them handle it.