"when one found a lost item in a city where both Jews and gentiles reside, if the city has a majority of Jews he is obligated to proclaim his find. If there is a majority of gentiles he is not obligated to proclaim his find"
"the item belongs to the finder, it is referring specifically to a place where there is a majority of gentiles, but in a place where there is a majority of Jews, no, it does not belong to the finder"

Babba Metzi 24a

https://web.archive.org/web/20201014222005/https://www.sefaria.org/Bava_Metzia.24a?lang=bi

Orthodox Jew writing to steal