Why Microsoft (probably) won't sue us for infringing 'IP'

LXer Feature: 23-Dec-2006 Opinion - August 2004, Microsofts Steve Ballmer warned Asian governments that Linux infringes 283 patents, some of which belong to Microsoft, and that those countries might experience trouble as a member of the WTO. However, nothing happened ever since (except more threats). Why doesn't Microsoft sue 'us', the users? Here are some more reasons you might not have thought of before.

Apart from the questions about if Microsoft knows what of their IP we, the Linux users, are infringing, are there other good reasons not to sue our ass? Of course, most of us are potential Microsoft customers, though that 'potential' may be very different between us.
Maybe it's nice to define who exactly is us. As a former maintainer of the LXer migration database, a list to keep track of governmental / non governmental organizations and companies who switched to Linux, it should be possible for me to sketch a picture of how 'us' looks like. Because if Microsoft sues 'us', 'we' should defend ourselves, shouldn't we? Some of 'us' don't have money, some of 'us' don't know anything about IP, some of 'us' don't care about infringing IP, and some of us are companies with lot of lawyers to pay. That last part of 'us' is the most interesting. However, in the case of Microsoft, there isn't any 'us', it's just Microsoft on its own. And that's where it becomes interesting.
When SCO (but we all know it probably was Microsoft in disguise) sued IBM and Novell, both Novell and IBM counter-sued SCO. That almost means, in this case, Novell and IBM cooperated to move SCO out of the way of Linux adoption.
Now, if Microsoft might sue some of 'us' for infringing their IP, who of 'us' could cooperate to defend Linux?
Of course, that would be Novell and IBM, since they earn a lot by using Linux, and Linux is crucial to them. Of course, Linux is crucial to Red Hat and SUN too. Those four could cooperate. Interestingly, whole Google wouldn't work without Linux. They are not selling Linux like Novell, IBM, SUN and Red Hat do, but they won't like being accused of infringing on the patents of Microsoft. Worse, the American and Indian army, and the French 'national police' rely on Linux. They won't be pleased also probably, being called 'criminals' for 'stealing'. Also, more and more municipalities - worldwide - rely on Linux. Even Microsoft may rely on Linux, for example when the Windows tablet PC of Microsoft Ukraine's boss, giving a presentation stops working, and they may use it on their servers. If Microsoft - on its own, without any community or coalition - is willing to make all this people - including the home Linux users who don't want to use pirated Windows versions - look like criminals, and if they wish to fight a legal battle against a 'coalition of the willing' Sun, Novell, IBM and Red Hat, I wish them a lot of luck, but it will backfire like a Saturnus V heading for their throat!