May 13, 2004

Microsoft: No Updates for Infringers

Microsoft, reversing a previous decision, says it will not provide security updates to unlicensed users of Windows XP. Microsoft is obviously entitled to do this if it wants, since it has no obligation to provide product support to people who didn’t buy the product in the first place. A more interesting question is whether this was the best decision from the standpoint of Microsoft and its existing customers. The answer is far from obvious.

Before I go further, let me make two assumptions clear. First, I’m assuming Microsoft has a reliable way to tell which copies of Windows are legitimate, so that they never deny updates mistakenly to legitimate customers. Second, I’m assuming Microsoft doesn’t care about the welfare of infringers and feels no obligation at all to help them.

Helping infringers could easily hurt Microsoft’s business, if doing so makes infringement a more attractive option. If patches are one of the benefits of buying the product, then people are more likely to buy; but if they can get patches even without buying, some will choose to infringe, thereby costing Microsoft sales.

On the other hand, if there is a sizable population of unpatched infringing copies out there, this hurts Microsoft’s legitimate customers, because an infringing customer might infect a legitimate customer. A large reservoir of unpatched (infringing) machines will aggravate an already serious malware problem, by making Windows an even more attractive target to malware authors, and by speeding the spread of new malware.

But wait, it gets even more complicated. If infringing copies are susceptible to existing malware, then some of the bad guys will be satisfied to reuse old malware, since there is still a population of (infringing) machines it can attack. But if infringing copies are patched, then the bad guys may create more new malware which is not stopped by patches; and this new malware will affect legitimate and infringing copies alike. So refusing to update infringing copies may leave the infringers as decoys who draw fire away from legitimate customers.

There are even more factors in play, but I’ve probably written too much about this already. The effect of all this on Microsoft’s reputation is particularly interesting. Ultimately, I have no idea whether Microsoft made the right choice. And I doubt that Microsoft knows either.

Posted by Ed Felten at 08:10 AM | Comments (46)