Fermenting in a freezer (with a temperature controller)

Obviously I'm talking about putting a bucket or carboy into the freezer and using a temperature controller to control the fermenting temperature.

Do I need to worry about the expelled C02 from the fermenting wort? Is the stuff going to slowly fizz out the door or will it build up, blow the door open, and spew wort everywhere similar to Poltergeist?

i dont think its anything to worry about. i had two in there for about two weeks now (just hooked up the freezer) and the only thing i could tell was that the freezer smelled delicous if you opened it!

thirsty,
I use an 8 cubic foot (Lowes) freezer with a Penn digital controller.
I CAREFULLY drilled a 5/16 hole at the top rear and inserted the probe.
I have made four, 5 gallon batches with this setup and found no problems. The Co2 vents thru the hole for the probe.
The thing also has a drain at floor level if needed
I have never had a runaway fermentation since using this setup.
Hope this info is of some use.
Joe