Break-ins in cave country in MX have been going on, off and on, for all the time I have been diving down there. But armed robbery has been very rare, and to date, to my knowledge, has involved the more remote sites like Angelita. Armed robbery at Tajma Ha, which is a common site for cavern dives, is a very bad omen. Honestly, as much as I love cave diving, and cave diving specifically in Mexico, were reports of incidents like this to become common, I would stop going there. For that reason, I think the Mexican authorities WILL attempt to find the people who did this; the Riviera Maya survives almost totally on tourism, and cavern tours are a significant part of it.