In truth, we know nothing of the sort (from RotS): Artoo was still the property of the Naboo government, but had displayed loyalty to Padme in particular, then to her children after her death. He simply left with infant Leia in the care of the Alderaani delegate, Bail Organa, rather than Obi-Wan with infant Luke. This would indicate Artoo was loyal to a cause (the infant rebellion), and not recognizing any claim of legal ownership: Padme after death was no longer a senator, thus her family had no legal claim to her "office equipment" (such as 'droids). Threepio seems to have been swept up as "salvage", memory wiped, and assumed he was property of the Captain afterwards. But title isn't a strong suit of the Star Wars films: salvage, sale of stolen property, murder, rebellion, an under-cooked form of government.Lord Revan wrote:actually we know that R2-D2 was "property" of the Alderaani royal house not captain Antilles personally this would make Leia as much if not more their master then the captain. Thus obeying Leia's orders wouldn't be a new purpose at all and while Astromechs do maintenance it's not their sole purpose they're more general use and yes that includes data carrying. I never said that droids aren't very intelligent and able to adapt but the issue is and has never been as clear cut as you seem to think it is.
I did pick up a copy of "Star Wars (A novel by George Lucas)" this weekend and found some of the particulars of this thread (Threepio's internal monologues and descriptions of the limiters built into 'droids to prevent independence, as well as some breaks from the movie and movie novelization canon, i.e. "Dark Lords of the Sith" [implying more, numerically, than just Vader, as special agents of the evil bureaucracy ruling the Empire, not the isolated Emperor], and the Death Star as Moff Tarkin's baby - let that sink in: the Death Star wasn't an imperial project, but a regional governor's.)
I also have some EU source books (or game source books) that mention the 'droid revolts in the ancient past of the Republic. I figured to leave those out, since it's former, lower-tier canon material.
Still, I have yet to see anyone defend the position counter to mine, that the 'droid characters do not display the necessary architecture for personhood.