Actually, in the First Contact movie, Picard tells Lily that he still has some Borg stuff internally, including nanoprobes, which is probably why he can still hear the collective when they are near. Similarly, in Unimatrix 0, at the end of the second part, the Doctor mentions that he was able to remove MOST (but not all) of the implants of Janeway, Torres, and Tuvok, and they were Borg for only a few days as well. I have to wonder what those 3 still have that are Borg - is it all internal, or is there visible stuff under their uniforms. They kind of dropped the ball with Torres when she first got pregnant, by not mentioning her experiences as a Borg and what effect, if any, that would have made on her pregnancy.