The Good. In some cases they may not be 'good' To elaborate. If someone has had a horrible day and they want to play some MC with their mates and do something productive but when they try to make their door someone breaks their workbench, they silently curse and act as though nothing happened and then their entire house gets filled with snow and some snowballs hit them too, That may be the final straw for them that pushes them over the edge.

The Bad. People who hate, do it because they have no sense of community. its just proof of there stupidity, the problem is that for someone on the receiving end they may be in a similar position as mentioned prior and this may make them stop whatever it is their doing. I have never let peer pressure stop me from doing anything so I don't fully get how it effects people but I know it does and when I can I try to help.

The pointless. 9 times out of 10 they end up giving the people on the server all the entertainment while they end up pissed since their banned. I remember so good times like that...

:D great job

Making a hole in someone's house for them to fall down in or filling a house with some block is good trolling without being too much of a jerk. I would never completely destroy anyone's house though as some of the more noobish trolls try.

As a trolling expert, I agree with most of this, but there are many more good trolling ideas out there. For example: making a dispenser and putting a bucket of lava in it, while it is rigged by a redstone connection in a wooden house. They won't know what hit them if you hide it properly, and the damage is nearly irreversible.