Glog

You can't - they're everywhere. Speaking of spam, check this out:

If you want to stop blog spam, do a google search for "mt-blacklist". Or upgrade to the latest pay version of movabletype, and turn on typekey authorization.

I use mt-blacklist, with a php script that update the list twice a day. It gets most of the spam out.

Thanks, Vivek. I scrubbed the shit out of this site with mt-blaklist.

For real protection, you're going to have to set up a script and cron job to update that blacklist every day or so.