fixing games and apps that are nolonger supported because the companys that made them nolonger excist is a valid use of decompiling.
and common , ms steals/theives all the time, just that they can afford to buy out those they theive from
also i have to bring up that i think "code" theift or "intelectual propertie theift" is a load of horse sh!t, sure if somebody steals my idea i may be annoied even angery but if i let them its my fault, and when it comes to programs and sorce i personaly feel that as long as the person who gets the code dosnt make a profit on somebody else work without paying them for their work that is all good.
yes i know its not technicly leigal, but every country has its own laws about this, some flat out refuse to accnolage intelectual propertie rights(good on them) others have diffent ways of viewing it, like the japneese, they will patent/copyright the USE of something b4 theres even a product/line of code/drawing of it, they patenet stuff like mad, everything anybody can dream up gets patented, it may never get built but it is patented, and if you go their with an item that does what a patented idea does, they own your item/invetion and can take it from your........crazy.....
so on that tangent i say FOOK MS, long LIVE the haxzorz, may they caust ms more $ as ms is trying to save by stoping them.