"It might seem counterintuitive to short a company as geographically diverse as telecom service provider AT&T, but short sellers are honing in on the fact that relative to Verizon Wireless, AT&T is being left in the dust with regard to 4G LTE-capable cities. Verizon has more than double the number of LTE-capable cities, giving it a definitive edge over AT&T and forcing AT&T to spend heavily to catch-up. Like Intel, higher expenses could reduce AT&T's earnings growth over near term, which is a perfectly good reason for short sellers to be skeptical.
Is this short interest warranted?
Although AT&T has underperformed Verizon in the growth department and in overall 4G LTE-capable cities, I'm not exactly sure why short sellers would ever bet against AT&T. With a minute beta of just 0.28, AT&T tends not to move much, which should automatically keep short sellers away. On top of this, AT&T pays out one of the top dividends in the Dow at 5.3%. With steady cash flow and a top-tier brand name, I'd suggest not joining these short sellers in betting against AT&T."
http://www.fool.com/investing/general/2013/10/05/the-dows-5-most-hated-stocks.aspx