I've seen it on the BBC news. The place is swarming with activists and reporters. Its definitely not being done in secret.
I would imagine that it would not be hard for the police to justify a raid to reclaim classified documents, but maybe someone more familiar with the situation than myself could explain why this is less likely than my paranoid mind tells me?
Except in other parts of the country, Crimea for example, pro-Russian protesters are taking over government buildings and staging their own protests...
There's even talk of secession in Crimea...
The pro-EU activists may be a majority in some parts of Ukraine, but not in Ukraine at large...