DG FastChannel 2Q profit declinesDALLAS — DG FastChannel Inc., a digital media advertising services company, said Thursday it earned a lower second-quarter profit, but matched Wall Street expectations.

ExlService Holdings 2Q profit falls, shares slipNEW YORK — Outsourcing company ExlService Holdings Inc. said Thursday its second-quarter profit dropped more than 50 percent, as revenue fell almost 10 percent, but its results met Wall Street estimates.

NEW YORK — Hackers on Thursday shut down the fast-growing messaging service Twitter for hours, while Facebook experienced intermittent access problems. Twitter said it suffered a denial-of-service attack, in which hackers command scores of computers toward a single site at the same time, preventing legitimate traffic from getting through.

Hackers attack Twitter, Facebook also slows downNEW YORK — A hacker attack Thursday shut down the fast-growing messaging service Twitter, and Facebook also said it was looking into possible site problems.

Twitter outage clamps tweets, cause 'unknown'NEW YORK — Twitter is down. For users of the short messaging site, this means no tweeting about lunch plans, the weather or the fact that Twitter is down.