I'm a bit slack with MSN as I tend to leave it until every couple of years before I do the housekeeping. By then, you get to the point of wondering who so-and-so@hotmail is.
I've only blocked a couple of users, mostly because they were complete and utter nutters.
As for a previous question, when you delete someone from your address book/contact list, it also asks you if you want to block them. This is the best time to do it, not after you've deleted them.
Even if you have deleted them off your list, they can still see if you're online, hence the blocking.

I'm not sure I have a life Sam, I've just not been on for ages. I remember to log on, find no one there and send lots of messages to be seen later. Give me a time and day and we need to catch up before you head over.

I'll text you !!