'Scare quotes' is not the only use of the double quote.
In this case it seems that the author is pointing out that the incumbents do not in fact have any inferred or conferred ownership of these public spaces.
In this case it seems that the author is pointing out that the incumbents do not in fact have any inferred or conferred ownership of these public spaces.
I decided to treat it as a minor typo and read it as 'people would be able to ignore and excuse the increased prevalence of "foreigners" on their streets' instead. Ie, the foreigners aren't really foreigners, just citizens of non-aboriginal ethnicity.
By putting the word their in quotes the poster is implying the unstated assumption that states aren't legitimate.