The rule is, when you exit customs and are outside the secure part of the airport you can carry with you.
If you are at a airport like Atlanta or Orlando, when you exit customs you are still in the secure part of the airport and liquids over 1 oz are not allowed.
This is just the way it is, and has been this way for years.
I have flown out of Orlando internationally 4-5 times a year for as many years and NEVER was this the case until my last trip last month. I regularly fly Delta and JetBlue and have also recently flown AirJamaica, AirTran and AA internationally and this was also NOT the case.