Having lived in Mexico for several years, I can say that probably the worst feeling I have ever had is that if anything ever went down, the police will not do ANYTHING. You are all alone and the whole society lives in fear behind big metal gates, knowing there is a worthless, TRULY corrupt police force. Many police will actually let the crime happen then rob you after when you are vulnerable, especially if you are a foreigner. When returning to the US, one of the greatest feelings in the world is knowing that if anything happens and you call 911 someone will come and do something. Might not be perfect, might not even work, but someone will come and try to help. Its a blessing I did not appreciate until living in Mexico and returning.