Government officials and media pundits are repeatedly saying Gaddafi is 'killing his own people,' but the rebel militia and civilians certainly do not consider themselves to belong to him. And why should it matter? Would it be more acceptable if he was killing people who lived a little farther away?
The entire reason these revolutions are taking off is because of their international character. It is fundamental to human nature to want freedom. When people are fighting the same thing in the same way at the same time, it's still the same movement despite geographic separation. What is being fought in Libya is the same, differing only quantitatively, as what is being fought in Wisconsin, Greece, Portugal, Yemen, the UK, Bahrain, etc. They are not "Gaddafi's people," they are people, and that should be good enough.