Just did a quick search, and some of the well-established communities (Formosa Gardens, Indian Wells, etc) don't use security systems (at least, the villas I checked didn't). Some of the newer ones, such as those on Hwy 27) do. Now it's got me curious to know how many do and how many don't, and if it's community-wide or just individual homes within a community.

Great question, NDGLB03!