B: Ordinarily if an intelligent being comes to Equestria seeking citizenship, they’d go through immigration. Pretty simple process. Barred from holding any government sanctioned position for a year, and within that year they must prove they’ve integrated into Equestrian society and are able to pay the tax. After that they’re an Equestrian citizen, free to bask in all the rights and protections that offers until such time that they are either unable to continue or prove themselves unfit as a citizen.

B: However, due to the changlings’ unique talent, things become much more complicated. Being unable to tell who may or may not have been involved in an attack against our nation, all changlings would have to be considered ex-criminals. They would be assigned a probation officer and a rehabilitation/reintegration councilor. The process of rehabilitation and reeducation would last as long as necessary- possibly a year, possibly more. After proving they’re able to behave within Equestrian borders, the process to become a citizen could begin.

B: Of course, you don’t have to live in Equestria as a citizen. There’s nothing illegal about being unregistered and without a temporary visa. However, you’re prohibited from engaging in any government related activities, like voting or receiving a permit, and are not protected under Equestrian law. If you’re not a citizen and you get mugged in broad daylight with a hundred witnesses, you do not possess the right to press charges. Somepony else would have to do it for you.