Answering my own question: we limit tv viewing time. I'm not especially consistant, and they watch either much more tv than our stricter friends, or much less than our friends who are junkies... During the school year, they don't watch after school until they are done with
all their homework. We don't watch during the dinner hour (unless we've been gone and happen to be eating late when "The Amazing Race," is on...

The little 'uns only watch until bedtime. Dd13 and I watch more mature shows after the little uns go to bed. The tv is in the same room as the computer, so I can "watch with" sorta kinda while being online so I don't go completely mad and turn into a televidiot, a horror to me...
I used to
hate reality shows as a real time waster- and was embarrassed that my kids
all loved "American Idol," and "Survivor Allstars," but it opened up learning moments for us all where we got to look inside how we came to value what we did and compared it to others...
I do monitor movies. If the violence or sex is necessary to the story plot, I am less upset by it than if it's not. If the plot is interesting, I am more inclined to let it in to our consciousnesses early... Like, I
loved "Spiderman," so my ds- then 3 saw it, too, and understood it... but I wouldn't let him see any of the "Terminator" movies although my dd13 has, and did at an early age (ds-now 21 got T2 for a present shortly after it came out- that's pretty violent, but has a complex story which needed the violent action, and I wasn't censoring strongly then.)
I'm rambling now, and since my censoring of media isn't set inflexibly for me, it makes this much harder to answer than how I censor what I say... Basically, it varies from child to child, and my concern is that they will sit and watch tv rather than go off and
be active more than a fear that the content will warp them somehow... but I still do censor to some degree, and it's based on what
I like to watch... and in some way, I think it might be similarly unhealthy to second-hand smoke (
for the mind?) Does that make any sense?