The latter can be particularly dangerous for a traveler who's not careful.
Despite the reputation of places like Cancun and Tijuana, Mexico takes a dim view of some of the more outspoken forms of debauchery. Shouting offensive words, carrying any kind of marijuana (even with a license or prescription) and even displays of nudity are all banned.
How seriously do they take this? Well, the movies on Aeromexico flights blur out any cleavage, so that might give you an idea.