In my opinion:
Using words in the academic sense, Andreus mentioned Stockholm Syndrome, other things, scientific terms, sociological terms, etc, totally fair game because of the impossibility of using anything else.
To use actual people's names, or place names as in, you use the name in association with that person/place specifically and personally and not with the idea/event associated with the place or with that person (ref. Kreditbanken robbery in Stockholm, where Stockholm Syndrome takes its popular name) breaks the fourth wall.
Helpful diagram:
"I was recently at Stockholm" Not Acceptable
"I think Andreus is suffering from severe Stockholm Syndrome" Acceptable
Or
"I am familiar with the works of Machiavelli" Not Acceptable
"Silas Vitalia recently poisoned her rivals at a banquet, bit Machiavellian of her to be honest" Acceptable
However, one thing I believe is broadly acceptable is angrams and combinations.
Say you're making an alt, Gallente, and want a fancy-pants name. But you don't want to spend an hour reading Homer's Odyssey/Old Maori Legends/The Tale of the 47 Ronin, so you just pick two names familliar to you and combine:
"Stanislaw Olbricht" - First word taken from Stanislaw Lem, sci-fi writer most famous for the novel "Solaris", and second word taken from General Friedrich Olbricht, leading figure in the July 1944 plot to assassinate Hitler.
Also using cultural language or terms in names is generally acceptable.