Geez touchy topic here. It's a shame no one has HARD CORE evidence to support their arguements. I had mine blocked off, just coz i was bored and wanted to see what it would sound like. I didn't keep like that for long. For those that want to know an easy way, go to REPCO or similar and ask for the rubber bungs they stock. Then just take off the rubber hose connecting the bov to the return line and bung up both ends. I'd like to think that having 'the flutter' would not cause any damage the the turbo (considering it sounds pretty cool lol) but it's hard to imagine why so many cars come equipped from factory with bovs. But alot of peoples posts make alot of sense. A couple mates have had their bovs blocked while running 16+psi for quite a while with no damaging affects. Each to their own i suppose, i mean even the chance of ruining your turbo sounds pretty scary.
My 2c