It may not be identity theft, but identifying someone for the sole purposes of harassment or public shaming is questionable.
I don't know of a case where someone has sued for defamation of character due to the presence of their name being on a scab list, but there are cases where people photographed walking out of abortion clinics and adult bookstores have been able to sucessfully sue those who posted their photographs on websites or billboards.
Yes, I'm sure the unionists will say a scab has no character, but in a legal sense of the term, if someone can prove damages in civil court, it won't really matter what the unionists or Jack London has to say on the matter....