A massive merger in the U.S. cable television, movie and internet business is a symptom of large and rapid changes in that industry. Combining AT&T with Time Warner boosted stock markets, but a social media expert says making large companies even bigger could hurt the innovation that is the key to survival. Some other experts say the combined company might have problems getting government approval. Home Box Office (HBO), which shows Game of Thrones and many other popular programs, is a cable television channel and part of Time Warner. The big company is the target of an $84 billion merger bid by AT&T, which is one of the biggest providers of internet and wireless communications and a conduit for television programming through its DirectTV service. The new company would unite a major program producer with a large company that distributes content. The proposal comes as cable television companies expect less revenue as customers turn to internet alternatives. An expert at the Silverback Social media agency says accelerating change in the media landscape makes innovation crucial to success and survival. Large, lumbering companies are slow to innovate, according to Silverback's Chris Dessi. "Two or three guys in a basement somewhere – they are in Silicon Valley – they are going to do something so compelling, it is going to change everything we are talking about in the entire media landscape," said Dessi. On the stock market, skeptical investors pushed down the two companies' stock prices, on worries that getting regulatory approval will be hard. But investors often see mergers as a sign of economic confidence, and the news sent overall stock markets up, according to the head of CFRA Research, Sam Stoval. "Why would AT&T be doing this unless it feels as if there is some growth potential, at least expecting that the economy could be improving over the next several quarters?" asked Stoval. CNN produces news programs seen in the United States and around the world, and is one of the companies affected by the merger of its parent firm, Time Warner. Critics say allowing the huge combined company to control so much news and entertainment media puts too much power in too few hands. Victor Pickard of the University of Pennsylvania said mergers may also mean customers pay more and get less. Professor Victor Pickard spoke via Skype. "One way or another consumers get hit in their pocketbooks and end up paying more on a regular basis. And many of the purported benefits that industry representatives claim will come out of this often do not ever materialize, at least not to the extent they promise," said Pickard. HBO, home to many dramatic films, is one of the major properties in the merger. There may be a bit of drama in real life as regulators decide the fate of this merger. Some experts say it has a 50-50 chance of success.