There's been ministerial interest in Freedom of the Pulpit again, so I've brought this post forward from July of 06, and added a bit to it.
iMinister defines Freedom of the Pulpit as freedom from advance censorship. This important doctrine exists to protect a minister from a demand that s/he "never speak of that issue" or "don't tell anyone what you believe about that." It exists because we cherish the integrity of the minister and because it is sometimes good for a congregation to hear things they don't want to hear.
Freedom of the pulpit doesn't belong to the pulpit, and you don't get it by virture of standing behind the thing. It is a trust bestowed on persons who are in covenant with the congregation to speak the truth in love, to honor the congregation's mission, to be fair, balanced, and wise etc. All called ministers, many hired ministers, and, if the congregational covenant is strong enough, members of the congregation can be said to be a part of this covenant.
Guest ministers are often granted Freedom of the pulpit by courtesy (If we didn't trust them, we wouldn't have invited them.) In my congregation, everybody else is asked to speak on a particular topic and, if there's any question about what they are going to say or how they plan to say it, we ask for a manuscript.
We do this more for reasons of quality and length control, than to censor their ideas, but neither I nor our worship committee would hesitate to disinvite a speaker who was not being truthful, loving, or productive about what they had to say. In practice, we mostly help people get their point across more effectively, rather than censor content, but I have done it once. (The speaker was a mile over the "no partisan politics in a non-profit organization" line. It made it easier that I could invoke the IRS on the matter and I managed to salvage the relationship.) We came to this policy after some difficult experiences.
A congregation will entrust its desire to hear many sides of the truth, spoken in many loving, careful ways, to its minister, worship committee or both. Those so entrusted must have and use some discression, because "Freedom of the Pulpit" is a principle meant to serve the needs of the people, not the egos of the mouthy.
"Freedom of the Pulpit", even for a called minister, does not mean that "you can't be fired for what you say, "
A minister who gets obsessed with one issue and preaches about it out of proportion to its importance to the members, who uses the pulpit to scold those who disagree, who preaches in a way that causes damage to the church's reputation in the community, and who does not speak responsibly about the pros and cons of the issues s/he talks about will probably be judged out of bounds of the covenant and can very appropriately be asked to make changes in their preaching subject, manner, and priorities. If the covenant stayed broken for long, the congregation would probably dismiss the minister by it's democratic procedures.