This is a friendly dashcam reminder of why it's important to use your parking brake if you park on a hill. You should also turn your wheels into the curb. Oh -- and always forgetting to disengage the parking brake when you get back in your vehicle and proceeding to drive around with it on for awhile is not a reason to not use it in the first place, it's a reason to reevaluate whether you should really be driving at all.
Keep going for the whole video.
Thanks to hairless, who not only uses his parking brake, but keeps rocks in his trunk to jam under his tires.