It looks like separatists did the deed. http://voiceofrussia.com/news/2014_06_29/Donetsk-militia-takes-control-of-Ukrainian-anti-air-installation-1561/
alternate source: https://twitter.com/StateOfUkraine/status/489802664264212480/photo/1 http://web.archive.org/web/20140717155720/https://vk.com/wall-57424472_7256 http://i.imgur.com/KJ0h3nZ.png
Recorded conversation between separatists: http://www.youtube.com/watch?feature=player_embedded&v=V5E8kDo2n6g
Subtitled: 17.07.2014. Bezler group terrorists have shot down a passanger plane Boeing-777 of Malaysian Airlines using air missile system. At 16:40 Bezler has reported to his coordinator GRU colonel Geranin Vasiliy Mykolayovich.
Bezler: "Just downed a plane. "Miner" group. It has fallen behind Enakievo.
Geranin: "Pilots? Where are the pilots?"
Bezler: "Went to look for and photo the downed plane. It's smoking..."
Geranin: "How many minutes ago?"
Bezler: "Approximately 30 minutes ago"
Subtites: After examining the plane terrorists have concluded they've downed the civilian aircraft.
"Greek" (apparently a nickname): "Yes, major!"
"Major" (same here): "Allright. So the "chernuhinskie" have downed the plane. From Chernuhinskiy check point. Cosacs that are located at Chernuhino." "The plane has colapsed in the air, around the Petropavlovsk mine. We found the first "two hundred" (dead person). It's a civilian"
Greek: "What's going on there?"
Major: "In short, [shit], its 100% a civilian plane"
Greek: "[Fuck] are there a lot of people?"
Major: "Fucking shit. The parts have fallen right in the backyards."
Greek: "What kind of plane?"
Major: "I haven't figured out yet. I haven't been to the main part. I am only looking where the first bodies started to fall. There are the remainders of inside connections, seats, bodies."
Greek: "Understood. Any weaponry?"
Major: "Nothing at all. Civilian belongings, medical remainders, towels, toilet paper"
Greek: "Any documents?"
Major: "Yes. Of Indonesian student. From Thompson University"
terrorist: "About the plane, downed around Snizhne - Torez. It came out to be a passenger plane. It has collapsed near Grabovo, there is a sea of dead bodies, women and children. Cosacs are looking at it now. They are reporting on TV that it is a Ukrainian transport An-26, but they say it says Malaysian Airlines on it. What was it doing on Ukrainian territory?"
M. Kozicin: "Means they were transporting spies. Shouldn't fukn fly there, it's war now'
Apparently the separatists have the black box and will only give it to Russia. This puts Russia in somewhat of a bind.