Xenon's Second Wager says that everything should be left to choice among the
only ones affected. In general, this seems good, given that the parties have
knowledge of what they agree to. (Less specifically, one can say that
"Everybody should be able to decide about something to the extent that it has
an effect on them"<1>)

However, in an imperfect real world, people rarely have the time or energy to
investigate all possible circumstances of an agreement, especially if it is
of great length and/or complexity. Such an observation leads to the conclusion
that whoever first drafts the agreement will hold power over the other to the
degree the other is not informed. The communication (be it an agreement, a
cause given to do something, or something else) can then be called asymmetric.

(Look around, and you'll find asymmetric communications attempts easily)

-

Previously, a "restriction of power" countermeasure was pondered on, going
roughly that "what limits freedom shall not be enforced". However, this is
unrealistic, firstly because freedom is a vague concept (will be mentioned
later), and because people may want to make temporary tradeoffs in freedom
(as is the nature of any sort of risk-taking process, or merely travelling
to another location -- in the latter example, you lose freedom of movement
to some extent because you cannot easily return).

One can consider freedom "the property of being unrestricted by external 
authority in one's decisions". (From this it is easy to see that a person
living alone in the world would have absolute freedom -- or rather, he
would only be limited by himself and the natural environment.)

If <1> holds, then we can show that knowledge becomes important, as it allows
someone to have a greater idea of what he is agreeing to, and therefore gives
him a greater possibility of being lead by external authority. (Consider this
as a parallel to soft force and hard force; leading by ignorance is soft force,
and set restrictions compose hard force.)

A definition based on property of being unrestricted also carries the advantage
that no matter the formal nature of the society or dealings with community,
it still measures "the right thing" -- e.g an authoritarian system clothed in
an appearance of free malleability is as much an authoritarian system as any
other. (The reverse also holds true, though the area in which such exists
is quite different from the previous example.)