Yield-chasing investors should be wary of AT&T (T -1.5%, 4.8% yield) and Digital Realty (DLR -5.4%, 4.6% yield), warns Jonathan Jacobson at the Sohn conference. AT&T's wireline ops are a "melting ice cube," Jacobson declares (revenue fell 1.8% Y/Y in Q1), and mobile competition is intensifying. As for DLR, he asserts "the data center [colocation] business is a commodity business" (ed: true, but it has been growing quickly), and accuses DLR of understating recurring capex. He also considers its dividend unsustainable without fresh capital-raising efforts. In addition to Jacobson's remarks, DLR appears pressured by Rackspace's Q1 miss.