Free: Not under the control or in the power of another; able to act or be done as one wishes.
That is, to take responsibilities for one's own action.
And in doing so, face the repercussions of those who you are willing to harm.
So the murderer of a homeless man will face the repercussions of the homeless man?
The polluter will face the repercussions of those who don't know they were polluted?
The thief will face the repercussions of the victim even though the victim can't afford to pay someone to find who the thief was?
In all of those cases, the perpetrator is
forced to act inconspicuously should they wish to remain in their state of lesser consequences, and their freedom is thus affected. The fear of being harmed is enough to persuade the fellows of those being harmed, that they must act to disarm the harmer would they be found out. The harmer has overwhelming incentive to hide, and the non-harmers have overwhelming incentive to remove the harmer (or themselves - flee) from their environment. If they didn't care about being punished (having a god complex), they may very well be punished by underestimating opposition, or be forced to defend themselves by destroying anyone that has cause to harm them (rebel), or to be isolated by the flight or extinction of prey.
One solution might be to kill all humans except yourself, then you'll mostly be free...but still subject to the whims of nature anyway.
The point of all this? None of us are free, and the modern world is the result of this duality between liberty and protection.
So is an American citizen living in Boston in his own house a free man?
No, save for the illusion of it. There is no available claim on this planet without contest, so the Boston man is shackled to a society (where can he go and stake an uncontested claim without an army?). His house is only his by law, the tenet of which is to refuse the freedoms of everyone else over that land. The system that gives him freedom over his own property is the same system that denies him freedom on every other. So, it is an illusion.