There is great truth in the statement, "One man's insurgent is another man's freedom fighter." While people in more peaceful parts of the world might not understand why fighting goes on in some places each one of the fighters is fighting for something they believe in. While we might disagree with their ideology or tactics, anybody that is fighting to end oppression is in a sense a freedom fighter.
Yes, freedom fighters do exist, and are the heart and soul of the United States. If something ever goes bad wrong, and we are invaded by another country, there are millions of people across the United States that are not actively in the military, but will stand up and fight.
I think in this day in age when it's not really too hard to shed light on atrocities around the world, that the concept of a freedom fighter is actually easier to exist now than ever before. Freedom fighters can bring attention to a multitude of issues and make a difference.
Just because the way the battle is fought has changed does not mean that someone fighting for their beliefs and cause can adapt as well. Rules have changed in battle to the point where there are almost no rules now. But I do believe freedom fighters can impact and change the cause they are fighting for. It takes one man to change the world, in a good way and bad.
This isn't the time of Braveheart or George Washington. Perhaps the last "freedom fighter" was Osama bin Laden even though he didn't really fight anyone. Individual freedom fighters don't exist. A fight for freedom needs to be done collectively as a movement as witnessed during the Arab Spring. Individual freedom fighters don't really inspire anyone in contemporary society as much as martyrs do.