The Mexica Movement is one of the many groups that would like to do a land grab of US territory in any way they can. Since both political parties have kow-towed to the illegal immigrant invasion the radicalized Mexicans who simply want to grab the border states for Mexico (or some new seperatist country) will start to fell confident enough to taunt the public like this.
Here are the symbols to looks for:
Inlike other radical groups trying to creat Aztlan, these folks are trying to liberate Anahuac. They want whites out of the USA and Mexico both. And why should the whites go? One reason is apparently because the whites are racist while they obviously are not. Although they do hate whitey.
Heres a backgrounder on the Mexica flag.