I don't like it, but I think I'd be more concerned if they were divesting themselves of continental US properties. The article doesn't say whether or not these numbers are the total purchased, or the net purchased (after subtracting out anything they sold)... so we don't know, for example, if perhaps they SOLD $30 Billion in properties in anticipation of falling real estate values after a massive terrorist strike.
I just don't like it because of all the "muslims take over the world" crap I read.