A new paper by David Yanagizawa finds tragically large effects of access to radio on violence in Rwanda, concluding that “hate radio” may explain as much as 9 percent of the genocide.
Aside from such blatant risks of propaganda through mass media, there are more subtle arguments cautioning against wholesale enthusiasm for greater transparency and information to improve governance and accountability.
Theoretical work suggests that greater information could be used for political “posturing” and “pandering”, reducing incentives to pursue actions that contribute to broad public goods. On media, the mantra seems to be independence from state control, which while probably necessary doesn't address other incentive issues in competitive media markets.
There is a growing literature on whether competitive media are "lapdogs" rather than "watchdogs"-- another paper title from Yanagizawa—although others have used it as well. Also, media have incentives to “slant” the news to cater to people's priors, instead of reporting unbiased information.
The relevance of such arguments is perhaps best demonstrated by the lack of systematic evidence that mass media improve the quality of public services.
Do media help to make public-payroll teachers show-up and teach in schools? Do they improve the implementation of public health programs? There is plenty of evidence, in contrast, that access to media helps some constituents get more redistributive benefits from targeted spending programs—for example, welfare in the US and disaster relief in India.
What media, what information, might facilitate greater demand (and government response) for better quality services?