Hack that forces all in-game player's game to close / crash?

Recently I was playing in a Stronghold Server and suddenly my game closed. When I rejoined the server, it was nearly empty and everyone said their game had force closed too. It’s obviously a hacker in the server which is no suprise. My question then is how can somebody even do this, should this be a concern and is there a way to prevent this. Also I should add that there was no crash error but it did generate a Crash Dump File.

What.
Why would it be a hacker? It’s obviously just a server malfunction. Are you dense?

[editline]5th July 2012[/editline]

Show proof of there being a hacker, or leave.

Lol, it doesn’t work that way…

There are a couple of game breaking glitches that can do that (that material bug which was posted here about a year ago for example. I am pretty sure thread got deleted) but I don’t think anyone in their right mind would post them here

It’s obviously a hacker

I hate it when people jump to conclusions.

On a more on topic note, It’s happened to me before many a time, it’s just a glitch or something.

Alright thanks for the replies, It’s not happened since. I thought it was someone doing it intentionally because it happened frequently and only when we talked about it in the server.