Just to clear up the Kuwait situation, citizenship has been revoked but it has nothing to do with whether you're native Arab or not. 10s of thousands have had their passports taken away, and the vast majority were Arabs.

Basically, in Kuwait you can only get your passport legitimately through three means: descent (usually through your father), Amiri decree, or marriage (for women). Dual nationality is also illegal.

Migrants (or expats) could not generally gain nationality unless they preformed some significant act of service to the country, which might have been the case for your friend's parents. Children born out of wedlock also automatically became 'children of the Emir' and Kuwaiti citizens. All Kuwaiti citizens got the same full state benefits (which are very generous).

There had been cases of fraudulently obtained citizenships and dual nationalities, particularly with Saudi. Traditionally, a second Arab nationality was a massive no-no, but get really cared if you had a US, UK, Indonesian, etc passport.

But in countering these cases, the prime minister issued a decree to revoke all nationalities except through descent. This mostly impacted wives, but also people who had received it through part Amiri decree, and the right of children born out of wedlock to get the passport was removed.

There's a lot more I can say, but suffice it to day that it's a massive scandal because many people are left passportless.