After hearing about how the UK 'Stop The War' website was hacked today, I've been looking into how easy it could be. Their site was based on the Joomla CMS (content management system) and it turned out that it was easily hacked if they hadn't updated the main source. I don't know if that's what happened, but it made me think about security here.
I found this site:
https://www.waraxe.us/
If you run a site, it's worth having a look around.