I recall FB became quite keen on not letting you target particularly small audience groups which would have made it even harder.
However, a friend of mine recently got an ad targeting his name with some custom clothing and was confused how it happened because Facebook doesn't let you target by name. My speculation (and I'm intrigued if anyone thinks this is possible) is because his email address is $fname@$fname$lname.com, an advertiser autogenerated a giant list of common first names and my friend's last name plus common email providers or domain name patterns, fed it into FB's Audience Manager, and then targeted all the ones that matched FB logins. A sort of dictionary attack, if you will.
However, a friend of mine recently got an ad targeting his name with some custom clothing and was confused how it happened because Facebook doesn't let you target by name. My speculation (and I'm intrigued if anyone thinks this is possible) is because his email address is $fname@$fname$lname.com, an advertiser autogenerated a giant list of common first names and my friend's last name plus common email providers or domain name patterns, fed it into FB's Audience Manager, and then targeted all the ones that matched FB logins. A sort of dictionary attack, if you will.