Damned Magpies!

I saw two maggies bouncing on the branches of a bush in the garden yesterday and I thought they were a bit too aggressive to be 'having fun'.  Sure enough they were harassing a Dunnock which was protecting its eggs.  I chased them away.  They came back, again and again.  When I checked the nest this morning there were two eggs missing and some broken twigs.  No sign of the pretty sandy brown/grey 'hedge sparrows' (aka Dunnock).  I suspect they've been eaten or scared off.  I dislike magpies so much.