Monopolies are a bad idea. The whole patent system is based on it. BUT I see no difference in monopolies on algorithms - with a specific purpose - than monopolies on chemical substances or mechanical constructions.
I really don't think the community should fight software patents, but rather the bad patent system as such.
I remember working for a wind turbine company. It could not sell it's best wind turbines in USA and Canada because of a patent on using converter technology in wind turbines. It is a patent of the kind "use known technology X in field Y." There is no invention in that, but a patent is granted anyway. I can see a patent on "use known technology X in field Y by method Z", if Z is a real invention. And then the patent is really given for method Z.