Billionaire activist investor Carl Icahn tells CNBC that the economy is on a “precipice” and the market is “schizophrenic”, but he still sees opportunities in some areas. Icahn says he sees plays in advertising, telecom, the Internet and bankruptcies, but he also says amateur investors need to be very cautious because another downturn in the economy could result in a “bloodbath”. And, he says he doesn’t understand why “any individual in their right mind” would invest in real estate investment trusts right now. In fact, he says real estate offers a good opportunity for shorting.