POOP on the walls.... why?

So my daughter has a long running history of pooping in her room and then spreading it ALL over.... It started when she was about one and a half years old and it has not stopped. Every few months she does it. Now she is three years old and I have to stop and wonder why.... why is she doing this? She knows what poop is, she knows it is gross she knows to go in the potty and all but then she goes and craps all over her room, using clean clothes to wipe herself and putting it on toys and furniture and walls.
I wonder when is the cut off age to start worrying about why they do these things? When can you say ok enough is enough you are WAY TO OLD for this!

She got a small spank and then she was put into the shower for a scrub down while daddy cleaned the room, then we made her help clean it and finally a time out while we steam cleaned the carpets (thank GOD for at home steam cleaners)

I have no real point to this except I just am frustrated and going out of my mind at times. She breaks into the kitchen, she steals treats from the cabinets, she trows toys out windows, she paints colors and draws on walls.... Time outs work temporarily but it feels like she has a two minute time span then she is back at it reeking havoc! I dunno what I am doing wrong...

Well I had no real point I just wanted to vent!

ttyl