Philistinians
Yes, it is pretty ridiculous that those who claim they have eternal right to Jerusalem are calling themselves "foreign invaders".
The term "Palestina" was invented by the Roman emperor Hadrian. The Romans wanted to rename Eretz Yisrael (the Land of Israel) after the Philistines, the longtime enemy of the Jews. Hadrian believed that by renaming the Jewish homeland after the Jews' archenemy, he would be able to forever break the bond between the Land of Israel and the Jewish people.
The name Philistines in Hebrew is plishtim, which comes from the Hebrew verb polshim (foreign invaders).