The growing availability of the technology is lowering the barriers to entry. One can now buy a cheap drone for as little as $30 in a toy store ($70 if you want it equipped with a camera). Keefe notes that the black-carbon detector the AP snuck into the China in 2008 cost about $4,000. A few years later the price had dropped to less than $300.

This has not gone unnoticed by the Federal Aviation Administration, which has invoked longstanding but controversial rules against using unmanned aerial vehicles for commercial purposes. The programs at the universities of Nebraska and Missouri have received cease-and-desist letters from the FAA. Both are responding by seeking certificates of authorization from the agency, but meanwhile state governments around the country are drafting legislation that could crimp drone journalism. This sets up yet another potential battle between First Amendment protections and privacy rights.

Drones have already demonstrated tremendous potential to serve as effective environmental monitors, but the possibilities for using sensors extends far beyond just attaching cameras to drones. Opportunities for gathering environmental and health data are particularly enticing in countries and communities where such data aren’t readily available.

I have spent the bulk of my career covering environmental issues in Asia, and one of the most frustrating aspects of this work is that I often operate in “data deserts.” In many countries and regions, a lack of research and information on environmental and public-health indicators, or the widespread reluctance of governments to share such data, make it difficult to report on basic pollution stories that we take for granted in the US. If journalists are able to collect their own data on, say, air quality or water contamination, that could radically change their ability to inform the public about environmental health threats.

The project I oversee, the Earth Journalism Network, will run a pilot project over the next year to examine the feasibility of implementing sensors in a real-world journalistic environment. With the support of our colleagues at the Internews Center for Innovation and Learning, this initiative should produce a toolkit to help journalists on all sorts of beats use the devices.

We’ll be exploring the significant hurdles to using sensors to help report stories. Apart from needing some facility with the use of new and possibly finicky technology, journalists also need good access to data analysis. Experts at a conference on sensor journalism recently sponsored by Columbia University’s Tow Center offered some bottom-line advice: Get to know a statistician.

Legal restrictions will always be a factor and vary from place to place. Particularly in authoritarian countries, governments may simply deny journalists the right to publish the data they collect. Even in the US it’s not clear where one actually has a right to collect data. Can you place sensors on public facilities or spaces, such as street corners or telephone poles? What about public buildings? Might publishing the data potentially contravene health privacy laws?

There are a lot of questions to be answered. More arise all the time, especially as we begin to see the huge implications of a society laced with ubiquitous sensor technologies. The journalistic community will have to deal with these issues, or one day we may end up fearing sensors more than censors.

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James Fahn is the executive director of Internews's Earth Journalism Network and the author of A Land on Fire.