'Carlos the ATC in Kiev' appears to be a plant, spreading disinformation to 'confirm' the assumption that MH17 was shot down by a missile. Here he is seen speaking to RT-Spanish in May. Was his face obscured to protect him 'for speaking out'? Or was it obscured to protect his real identity from being exposed?
Matthew Bennett, editor of The Spain Report, has debunked one of yesterday's many disinformation campaigns. Yesterday, a man who identified himself as "Carlos,"supposedly a Spanish air traffic controller working in Kiev, made many fantastical claims on Twitter about yesterday's events. According to Carlos, two Ukrainian jets shot down the airliner, and soldiers were raiding his traffic control tower in Kiev as the story was unfolding.

Bennett has received confirmation from the Spanish embassy that "Carlos," a man who made similar claims during the Maidan protests, does not exist. Bennett tells us that, "he was posting yesterday that he was a Spanish controller in a tower that was taken over by soldiers as events unfolded. As far as I know, he was the source of the 'MH 17 tailed by two Ukrainian fighters' story. He's been quoted quite a bit on RT [the Russian state-operated propaganda network] since yesterday, and gained several thousand new Twitter followers in just a few hours."

The Spain Report posted this note on their Facebook page:
Full reply from Spanish embassy to The Spain Report via e-mail on the existence of "Carlos, @spainbuca, the Spanish air traffic controller" in Ukraine:

"This is not the first time we have been asked about him. This "Carlos" was also active during the Maidán revolution in Ukraine.

We have no knowledge of "Carlos" having been in Ukraine. There is no record of his passing through the Consulate, and no one from the (relatively small) Spanish colony knows him.

The airport where he supposedly worked for several years told us at the time that all of their air traffic controllers are Ukranian, and that in any case they have never employed any Spaniard for that or any other task.

Furthermore, the last information he was posting before the airline tragedy was of the same sort. He was saying, for example, that he lived in Kiev and had been threatened by radical extreme-right elements. No Spaniard or national of another country - to my knowledge - has ever been threatened in this country."
As of now, Carlos's Twitter account appears to have been removed.