Google's P/E ratio is ~21 at the moment, and their share price is ~$620.
They floated at a P/E ratio of ~100, and a share price of $85. Their share price would have to drop to below $85 for it not to be good value as an investment, and they would have to drop revenue to around 1/10 the current level for them to be earning less.
Even if I accept the likelyhood that there will be some kind of recession in Europe are you really saying that Google will drop revenues by 10 times? (I'd point out that during the 2008 financial crisis it reduced their revenue by a couple of percent).
