I know that we all have our favorite ventriloquists. Someone that we admire and would like to be like. But when does being like someone turn in to stealing their routine? That is simple. The bottom line is to come up with your own routine. Learn how to write comedy. Anyone can steal a joke but it takes a real talent to write you own material.
Stealing a show even goes into more detail when we talk about stealing characters and effects. Now I'm not going to go as far as saying that you should never use your hand to do ventriloquism like Senior Wences. But you know what I'm talking about. The day someone comes out with a sock puppet that is a lamb is the day that I believe Mallory Lewis has a right to a court case.
Mind you not all ventriloquists are going to get upset but, from my experience, the ones that steal the most are the ones that aren't that good. So when you have someone copying your material and they aren't that good it really becomes a problem. No wonder Ronn got upset when someone said they had seen his show before and they hadn't. They had just seen a bad ventriloquist steal his whole Mask routine.
Bottom line, if your going to use a line from a vent routine, get permission. And just never take someone else's routine, make your own and make it fun! God luck and happy venting.