I’m pretty sure some of these executions would break the law in places other than Mexico City, but I found it very interesting that Halo 4 is so mainstream they would consider doing a grafitti guerilla campaign in the city. Some executions below.
I even saw the slogan stenciled in the main ringroad of the city. Crazy! Although, admittedly, being the marketing manager responsible for that budget must have been a lot of fun ;).