"Revealing that we're spying on our citizens" == "betraying the country" - at least in the mind of the powers that be, both in Germany and in the US.
And, in fact, it makes a certain kind of logic. Per dictionary.com, treason means acting to overthrow one's government or trying to harm or kill the sovereign, but it includes giving aid to the enemies of one's government. Revealing where the government is spying on people may in fact give aid to the enemies of the government.
Now, in a free country, that's balanced by the peoples' right to not be spied on by the government. The people have a right to know that the government is crossing that line. (And, in fact, the definition of a free country might be one where the people, rather than the government, are the real sovereign.)
But no, it wouldn't be espionage. Espionage would mean that they were themselves spying, which is not the case.
And, in fact, it makes a certain kind of logic. Per dictionary.com, treason means acting to overthrow one's government or trying to harm or kill the sovereign, but it includes giving aid to the enemies of one's government. Revealing where the government is spying on people may in fact give aid to the enemies of the government.
Now, in a free country, that's balanced by the peoples' right to not be spied on by the government. The people have a right to know that the government is crossing that line. (And, in fact, the definition of a free country might be one where the people, rather than the government, are the real sovereign.)
But no, it wouldn't be espionage. Espionage would mean that they were themselves spying, which is not the case.