Partly, Microsoft themselves since they withdrew significant parts their patent claim pretty much as soon as they were forced to make them public:

http://www.zdnet.com/blog/microsoft/microsoft-withdraws-one-...

But you can judge for yourself:

"Loading status in a hypermedia browser having a limited available display area":

http://www.google.com/patents?id=DwEJAAAAEBAJ

"Remote retrieval and display management of electronic document with embedded images":

http://www.google.com/patents/about/5778372_Remote_retrieval...

"System provided child window controls":

http://www.google.com/patents/about/5889522_System_provided_...

"Selection handles in editing electronic documents"

http://www.google.com/patents/about/6891551_Selection_handle...

Take the "loading status" one for instance: the entire patent consists of displaying an animated graphic while a page loads and then removing the animated graphic afterwards. That's supposed to be an invention worthy of protection because otherwise Microsoft might keep its implementation secret, thus the public should wait 20 years to use it. In my view, that is exactly the kind of patent that makes a mockery of the patent system.