The Basis of "Based"
My brother, who I love dearly but who is very very odd indeed, often says to people "I'm (or he or she if referring to a third person) based in Toronto." Listening to the Ricky Gervais podcast the other day, I heard Ricky's writing partner Steve Merchant solicit emails by saying "If you're based in the US, Canada or Australia..." Based. Not LIVE IN. BASE. I am BASED here, she is BASED there, he is BASED up his own ass.
People, unlike companies or Goodyear blimps, are not BASED anywhere. They live places.