In the part of Santiago de Cuba where I was staying, it was very common for houses to have their doors, windows and balconies protected by metal cages (known as rejas). The installation of these was carried out by private individuals and it seemed to be good business, as they were much in demand.
Many were very decorative, which led me to conclude that they were primarily installed due to their aesthetic value, rather than any risk of crime that needed to be guarded against. However, one night at the house above which my apartment was situated and whose front entrance we shared, the owner of the house was awoken in the early hours and observed a masked man attempting to gain entry and cutting the wires to the buzzer that sounded when the gate was open. The intruder ran off when he saw that he had been observed. After that, I was glad that my apartment was protected by its own cage, attractive or not.