this is short and sweet. where can i find a business who makes those see through panels you see behind the news anchors sometimes? you know, the ones that have a little pattern in them so they bend the light just enough that when you put a bunch of tv screens behind them, it shows different channels but you cannot make them out clearly?
I think this is best, and most simply, done with distance. The depth of field between the subject and the background takes care of the rest. The distance between subjects and monitors also makes proper set lighting a LOT easier.
I know I wouldn't want to put a big (and I DO mean big), expensive piece of glass (or some other clear or semi-clear substance) on my set that would work under all the shooting conditions I'd encounter unless I absolutely, positively had to do it. If my monitors were too small at the desired distance, I'd get bigger monitors.
You can do this with a clear piece of lexan or similar and then apply a blurring stick-on film to this. Such film is available at home centers (for masking bathroom windows) or try the online catalog at Outwater Plastics, they are a huge source of stuff for set builders. They sell several versions of the film that can simulate frosted glass to various degrees. Try putting the film directly on the TV monitors, it should cling well using static electrcity. You can also chemically etch plastic youself using a solvent, but this takers some skill to do well and evenly. You could also use a diffusion gel material.