What Protections Exist for Parody Sites?

jolchefske asks: "I'm a small time guy running a small time parody website of a medium sized school district. My site lampoons the real website of the Seattle School District -- a district currently over 30 million dollars in the hole due to accounting "irregularities." My question is, what protections (if any) do parody websites have against copyright litigation? The district is 30+ mil in the red but they've got the lawyers knocking on my door."