"That seems to me like a very weak deterrent to stopping crime or terrorism related activity"
Fair enough, but that is subjective...… for instance, if you were the main bread winner with a family and have deep ties in where you live, and you knew that you faced immediate deportation if you were conclusively found guilty of "crimes against Britain" or whatever they may want to call it or enforce it..... and your family was comfortable and doing well in the UK, I definitely do believe that it would be a huge deterrent to openly start preaching hate speech about Britain on the streets as has happened in the past, or online like this guy decided to do.
"I absolutely support deportation of anyone engaging in terrorism or criminal acts, but only after they have served their prison sentence first. I'm pretty certain this is how most countries including the UK operate when it comes to crimes committed by a non national in their country"
Good point, my main issue I have with all of this, is that the guilty party should never have the benefit of living in the same country that he wants to attack and destroy, when found guilty of that kind of crime, so I would accept the prison time first, then deportation..... but definitely not what is currently happening now, which is serve your time, go back to the same streets and continue enjoying the luxuries and benefits of the UK lifestyle.... the lifestyle you openly want to decimate.