One letter can make a big difference. When talking about sensor journalism, you must take care to note that you’re referring to sensors with an “s”—the shiny new tool in journalists’ storytelling toolbox—not censor with a “c.” Mechanical devices that monitor all sorts of biological, physical, and social data, sensors can provide vital insights into our communities and the world around us. Particularly in the fields of public-health and environmental journalism, they are already enhancing news and feature stories and have potential to generate investigative reports.

But as with any technology, the implications of using sensors are not all benign. And there are questions, in the US and around the world, about how governments and other sources will respond to the use of sensors by journalists. Think of what the paparazzi or ill-intentioned snoops will be able to do once they master the use of aerial drones armed with cameras. The power of individuals and organizations to monitor ever more intimate details of our private lives raises ethical, safety, legal, and even constitutional questions that societies—and legislatures—are only beginning to grapple with.

Thanks to several trends, the use of sensors by the media is becoming more feasible. Most important, the devices themselves are becoming cheaper and easier to use. Combined with Web-connected microprocessors, sensors are the underlying technology behind the nascent “internet of things“—the increasing interconnection of machines and appliances. Also known as “machine-to-machine technology” or “ubiquitous computing,” this is what enables people to, for instance, watch nanny cams through their phones or start their cars remotely.

In terms of hardware, sensor journalism has been greatly aided by Moore’s Law—the steady progress of electronic miniaturization, which has resulted in computer power roughly doubling every two years—and the rise of the “Maker” movement, which emphasizes do-it-yourself manufacturing. By tinkering with sensor technologies that are rapidly shrinking in size and price, homegrown experts as well as academics are making them ever more accessible and easy to use.

The other important trend is the rise of data journalism that interprets, visualizes, and reports on the flood of statistical information being generated by everything from satellites to subway cameras. In open societies, much of this data is publicly available—so much that it has generated privacy concerns, as when the Journal News used public records to out gun owners in Westchester County, NY.

In many countries, however, particularly in the developing world, data journalism is constrained by a dearth of publicly available data. Even in wealthier nations, information on sensitive topics, like toxic contamination or radiation levels, can be hard to come by. But enterprising journalists increasingly generate and collect data themselves, particularly in the fields of health and environmental reporting.

The Associated Press is a good example. The news agency partnered with the Spatial Information Design Lab at Columbia University to measure and report on air quality at the 2008 Beijing Olympics. Today, the sensor they used can be mounted on a bicycle to take roving measurements. It’s even possible to get “aircasting” readings by adapting a mobile phone.

There are many other examples of journalists and others using sensors to monitor the environment. The Public Lab used cheap balloon-carried cameras to observe the effects of the BP oil spill in the Gulf of Mexico in 2010. Earlier this year, WNYC, New York City’s public-radio outlet, created a popular “Cicada Tracker” and asked listeners to build their own sensors and take soil-temperature readings to help monitor when Brood II would emerge. The Qatar Foundation is supporting the monitoring of mangroves to track their ability to sequester carbon. OpenIR at MIT’s Media Lab is measuring flooding in and around Jakarta with infrared sensors, which can also be used to diagnose vegetative health—crucial in analyzing deforestation trends.

Sensors also are being used to record gunshots and analyze where they came from, follow adventure sports, even keep track of a journalist doing a car review. John Keefe, a sensor journalism pioneer who launched the cicada project at WNYC, is looking into how sensors can be used to track management of public housing. Sensors in the form of EEG monitors worn around your head can measure how much attention you’re paying to something.

Camera-equipped drones are probably the highest-profile example of sensor journalism, and they are becoming increasingly popular with news operations. They have been used to augment or replace costly helicopter flyovers and to monitor wildlife. Drone journalism is in its infancy, like the rest of this field, but the University of Nebraska-Lincoln has a lab and the University of Missouri a class devoted to the practice. There is even a Professional Society of Drone Journalists.

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