I don't think the referendum was a particularly convincing one, but illegality under the law of the state being seceded from isn't a very convincing argument either. I mean, Ukraine's secession from the USSR was not legal under Soviet law. And Kosovo's wasn't legal under Serbian law. Consensual secession referenda, like the upcoming Scottish one, do happen on occasion, but are fairly unusual.

Legal or not they do seem to represent the will of the people, http://www.aljazeera.com/news/europe/2014/03/crimea-celebrat...

You do realize that when a region is under strict military occupation, those who oppose the occupation cannot exactly openly voice their protests, while those who like it, can. There is a portion of the population who support the annexation of Crimea, but you cannot make any real judgement of it's size by the data we have. (IMHO It's probably >50%).

I'm not going to claim that I know one way or the other (I think it's pretty difficult at this point) but here's another data point, http://humanrightsinvestigations.org/2014/05/12/pew-poll-cri...

What evidence is there that during the vote there was "strict military occupation"?

Among other things, the statements of Crimean Ukrainians and Tatars who have since then fled the place? If you were not part of the Russian majority you very much have to keep your head down.

which probably makes the title on the map debatable