The Ugly (you fill-in the nationality)

It's funny how two people can read the same thing and come to very different conclusions.

"If the land on which development is to take place in Barra de Potosi has been purchased by a private developer, marching in protest to such planned development by foreigners is permitted."

Then I asked so is it a private development or not, and ZihuaRob confirmed that the land is owned by private developers and that a for profit corporation (a Sociedad Anonima de Capital Variable) called "Fonatur Port Operating Company" that the Mexican government owns shares in is involved with it. They needed a concession from the government to be allowed to do what they want to do, because they are, by definition, not the government.

I don't see where you get "Frostbite did ask the actual authorities and they told him foreigners certainly could be deported for participating in this demo" from that. It's all a matter of perceptions, I guess. Sure, if they really wanted to they could make your life miserable. But, they can do that anyway. This is a few degrees removed from "interfering in the political affairs of the country", not like going around canvasing for a particular political party or something.

So whatever the law actually is, I don't think Mexico should be allowed to treat people like that. The Mexican government is always demanding that the US respect the rights of migrants in the USA, therefore they should respect the rights of migrants in Mexico as well. The subjection of foreign citizens to arbitrary arrest and expulsion at the whim of any authority who deems an action even remotely political seems like a giant violation of the spirit of things like the Universal Declaration of Human Rights.