Well, it depends on how you look at it.
Since we are in America (well most of us), yes, because we are not supposed to be able to make those. It is only for the Asians that created that system. See, Yahoo! is set in different ownerships for each region...so I guess they decided to let people make e-mail's (and ID's) with dots, like Google's Gmail allows. Apparently, it is called Yahoo! Gmail, I did a little more research and it said that.
So yeah, right now they are "illegals" for us having them. But, since you can make them now, they aren't really illegals. You see what I'm saying?
In one sense they are to us since we aren't really supposed to be able to make them, but then again they aren't because we are able to make them, even though it was made only for the asians. (I say Asians because I'm not sure exactly which part is "CN")
I still am happy, it's pretty cool
*Update* Looks like they are working on the word verification system, and I can't get past it. I think they're trying to stop bot programs...it will probably be working again tomorrow, sorry!