As already noted, Sam Warburton got three weeks for the tip-tackle on Vincent Clerc for which he was sent off.
The Decision is now available and can be read HERE.
The Judicial Officer (JO) was Christopher Quinlan QC, who dealt with the other cases in the RWC that I've already covered here. Suffice to say, it's therefore not all that surprising that the sentence was on exactly the same lines as the others, and covered largely the same ground.
It's also fair to say that there's universal sympathy for Sam Warburton, even from the JO. People know he didn't mean to land Clerc on his neck, and would never do it deliberately; it's just that the risks are so high that there has to be a deterrent, as the JO observed.
And that approach has spread. I've mentioned Justin Tipuric's citing; he also got three weeks for a more innocuous tackle in the Munster-Ospreys game (I'd link the decision but, thus far, it looks like the new RaboDirect Pro12 is keeping the old Magner's League policy of not publishing decisions). So, the crackdown is definitely on, and it's worldwide. If the tackled player is lifted, and comes down anything other than arse-first, the tackler is in trouble.
If (God knows, stranger things have happened), there are any professional players or coaches reading this, once piece of advice I would definitely give them is this; don't lift in the tackle. Just don't; it's too easy for something to go wrong, and if it does, you're going off. Instead, go for what has been one of the most successful defensive strategies this RWC; chop, drop and steal. Go low, bring the ball-carrier down, and the next man in jackals the ball. Ironically, Wales, with Warburton, have been one of the very best at this; but Pocock and McCaw have been superb as well. There's a piece by Shaun Edwards of Wales from the Guardian HERE that's well worth a read on this.
But, there's no question; the crackdown on tip-tackles is on, and will be for the next few months. Those in the game would be well advised to plan on that basis.