The actual mission was called Operation Neptune's Spear. Osama bin Laden's code name as an individual was Jackpot. If he was captured or killed, the code word was Geronimo.
It's the last one that has a number of Native Americans upset. I've seen it characterized as racism, an insult to a revered Native leader, and as an example of the colonialism that lingers in America. Some have also likened it to other instances of cultural appropriation.
I'm having a hard time articulating my thoughts on this. I can see how it's offensive, but it was a Latin nickname given to a Native American leader by Mexicans, a name used by many (non-Native American) people of many ethnicities both today and throughout history, and the motto of the 501st Infantry Regiment. The man history remembers as Geronimo was actually named Goyahkla.
So I guess the thing is that I view this as a fairly offensive choice in code words, but it's also a good opportunity to educate people on who Goyahkla actually was.