What is Freedom of Speech?
I define it as an individuals right to speak that is in line with their set of personal values. An individuals right to speak to defend their liberties and moral ideals.
What is Treason?
I define it as someone going against their country, going against what the country stands for (or at least what the government at the time stands for). Treason in it's most extreme sense, could also be seen as someone plotting the downfall of their country (or what the government at the time stands for).
Treason for me is really going against the sitting government because I don't think anyone would want to relinquish their national identity. E.G. German citizens plotting to assassinate Hitler, they're still Germans and want to be, they just didn't like what their government was doing.
So, what if there is some person who says something that is not in favour of their country? What if they have a view that is different to that of the sitting government? What if the government is trying to conceal something that affects it's citizens or is violating human rights? Is a whistle blower a traitor?
The line between freedom of speech and treason is very fine ... that's if we are talking about democracies (and even then there are exceptions). What about those protesting for freedom in Libya? Military personnel who told the world about what happened in Abu Ghraib prison? Are they all regarded as expressing their right to speak? Or are they traitors? Hmmm .....