what is "celebrity colonialism"?

The worst example might be Brad Pitt and Angelina Jolie's temporary annexation of Namibia as a "special" place for Ms. Jolie's labor.

The article linked above contrasts Brangelina's actions with those of European powers that formally controlled Africa for decades. But much of that formal control was only extended because of the actions of opportunistic individuals like Cecil Rhodes or King Leopold II of Belgium or, in fiction, Joseph Conrad's Mr. Kurtz. Actually, the best parallel is probably Henry Morton Stanley, whose books and newspaper stories probably made him as close to a movie star as one could get in Victorian times.

This is not to suggest that Pitt or Jolie have caused suffering at anywhere near this level -- their intentions toward Africa seem entirely benign. But the point is that if they can take over an entire nation at a whim to have their child, they could probably do anything else they want.