It seems that many people adopting these complex reptiles aren't really prepared to take care of them. Here's a list of incidents from just Florida alone:

January 11, 2008 / Key Largo, FL: A 10-foot-long Burmese python was discovered dead on U.S. 1; the snake was the seventh python found in the Florida Keys in the past nine months. (The Key West Citizen)

December 7, 2007 / Vero Beach, FL: A man mowing grass on the banks of a canal west of Vero Beach accidentally ran over and killed a 16-foot python. Vero Beach's Animal Control Officer told a local newspaper that the snake was the 20th large python or boa constrictor found in Indian River County in the past 10 years. (Vero Beach Press Journal)

November 24, 2007 / Christmas, FL: A landlord found a Nile monitor lizard in a cage at an abandoned mobile home. (WKMG Ch. 6, Orlando)

October 27, 2007 / Port St. Lucie, FL: A man was hospitalized after one of his pet snakes, a diamonback rattlesnake, bit him on the hand. Word of the bite panicked other residents at the Port St. Lucie condominium complex. One resident told local media about a previous incident in which a cobra had escaped from the man's condo. (Palm Beach Post, WPTV Ch. 5)

October 25, 2007 / Summerland Key, FL: A fourteen-foot python was discovered in the bushes in a parking lot in the Florida Keys. The snake was later claimed by a man who uses the snake to sell photos to tourists in Key West. The man explained that the python had been on the loose for two days; he was cited for allowing the escape of captive wildlife. (FWC Field Operations Weekly Reports)

October 24, 2007 / Tallahassee, FL: Four venomous snakes, including a King Cobra, were discovered in an abandoned storage unit. The animals were in poor health and may not have had food or water for weeks. (Central Florida News Ch. 13)