Even microsoft(or people at microsoft) are using illegal software o.o.
Long time ago, someone opened a wave file of Win98 with an editor, scrolled down and found the sentence:
Created with <softwarename i cant remember>
registered to <username i cant remember>
Well...the username was a very popular cracker
.
Ok but back to topic: If you use Legal software, do as sugested and let him/her sign a contract. If you use GIMP+blender+ purchased version of GS, you have all you need for creating content that is as good as content created with Photshop and Maya.
I use gimp and its an excellent freeware tool for 2d Art.
Greets
Rackscha