Well getting Putin mad does have a downside! I mean you could end up hairless and glowing, writing mean letters on your deathbed.
Maybe the polonium was used for that reason. What a red flag,,it screams "crazy Russian ex KGB"
http://www.freerepublic.com/focus/f-news/1747654/posts
I think that's it exactly. There is deniability, but everybody thinks Putin reached out and nailed a guy who may have thought he was safe running his mouth in the UK. Putin is a thug who knows all about threats. He knows how to make them and how to use them for political advantage.