Skyrim free dawnguard?

Yesterday i saw skyrim was updateing on the steam client,nothing unusual there only that it sead it was a 700mb update and thats a HUGE update.

So i loaded up skyrim today just to see what the update was all about and the game started dawnguard vampire's atacking me....so i looked in my data files and shurenuff the dlc is in my skyrim data files.

I havent payed for any of the DLC for skyrim on pc as i was given a copy of skyrim on the xbox i got the dlc's there because they were just out weeks before pc.

Has anyone else noticed a 'free upgrade' on skyrim or is it just a mess up with steam?

Very strange but atleast i get to play dawnguard again on pc.

I don't know. I already had dawngaurd for a while

[EDIT] Ok it seams steam whent and gave out millions of copys for free by mistake lol so if you dont have it have a look to see if you did get it for free....if you reinstall your computer for any resion you will lose it becase stean dosent show you as haveing it.

http://www.steamgifts.com/forum/mJNlF/bethesda-is-giving-us-dawnguard-for-free-its-over-glitch-fixed

I bought the Legendary edition, and where are all of your mods?

I havent installed many yet i only got skyrim in the steam summer sales and i havent realy had time to play it ive still got around 30 outher games i am still playing lol sale's lately are makeing me have far too meny games to play.

I got it during the summer sale too and I've put 131 hours on it lol.