Is it legal to sleep on the beach? overnight of course...?

I think it would be romantic and adventurous! I know that at the beach on the end of Palmetto Road in Boca Raton, the cops come around shining floodlights on all the couples at around 10 or 11p. Any other beaches where it is illegal? Anyone ever tried this before? I live in the tri-county area, so any beach in Miami-Dade, Broward, or Palm Beach county will do! Is it legal to sleep on Ft. Lauderdale beach overnight? South beach?