He's against software copyrights (in their current form) but he's not against trade-marks, for example, which are usually included in the vague term "intellectual property".
Stallman repeatedly condemns the use of the term "intellectual property", because it: A) lumps together a bunch of unrelated/dissimilar things (Copyrights, patents, trade marks, trade secrets) and B) because it implies that they are all "property" and should be owned, like property, perpetually.
Stallman repeatedly condemns the use of the term "intellectual property", because it: A) lumps together a bunch of unrelated/dissimilar things (Copyrights, patents, trade marks, trade secrets) and B) because it implies that they are all "property" and should be owned, like property, perpetually.