WHEN faced with adversity, John McHugh, an Irish photojournalist, reacts stoically. Even a bullet to the chest in Afghanistan in 2007 left him largely unfazed—he knew full well the job carried risks. But get him started on how photos are routinely appropriated and spread without credit or compensation, even by major media outlets which ought to know better, and he bristles. So much so, in fact, that he joined forces with a software developer to do something about it.

Current copyright law in the United States and Britain is lenient with respect to the use of photographs or other materials that lack identification, whether for commercial, editorial or personal purposes. So long as the user removes the content (and sometimes, albeit rarely, pays a fee) when the rightful owner speaks up, the odds of winning damages are slim. In 2010 a clause was mooted in Britain's Digital Economy Bill that would have provided even greater protections to websites and print publications. The bill offered broad indemnity to publishers of so-called "orphan works", which are under copyright but whose owner is unknown or cannot be found. The clause was snipped before the bill became law, but photographers remain wary. Whereas a quick web search is often enough to pinpoint the author of a text, the same is not true for photos. Without a credit, publications can reasonably claim ignorance.

Photographers have long been able to embed copyright and attribution information into images using metadata, text that image-editing software and other programs can read and which is stored alongside the pixels of a picture. But these metadata tend to be stripped out as images are uploaded, resized and shared on social networks, to say nothing of specific tools that get rid of metadata in order to obscure a picture's origins. This helps preserve privacy (metadata can contain a camera's serial number and GPS co-ordinates). But it also makes life easier for those who wish to disseminate images without proper attribution.

Marksta, launched on January 3rd, aims to put paid to such practices. It uses drag-and-drop resizing and positioning to etch text onto an image created or loaded onto an iPhone. The credit can be placed anywhere on an image, or as a repeating border. The choice of colour, font, drop shadow and other garnishes ensures the final product does not look tacky. Moreover, unlike many existing apps, Marksta requires no registration and collects no personal data. All this makes it simpler and cheaper than hiding information within the image data using subtle patterns, a complicated technique known as steganography and championed by Digimarc and others. If successful, Mr McHugh will add optional paid features geared towards professional users, as well as iPad and Android versions.

Although Mr McHugh lugs around digital SLR cameras on many assignments, like many professional photographers nowadays he often relies on a smartphone, especially when he has to cross a border without raising suspicions, as he did during the Arab spring. In any case, a mobile device is less conspicuous and does not prompt subjects to start posing, as often happens when a proper camera is present. It also lets you upload pictures on the spot. (In many countries mobile data networks kept functioning throughout the turmoil.) Fond though Mr McHugh is of this feature in principle, he has been reluctant to embrace it in practice for fear that someone might appropriate his unsigned work once it has been posted online. Marksta allays this worry.

Mr McHugh admits that the app's simplicity also means that its watermarks are easy to erase. But the point of Marksta is not to make airbrushing credits out impossible, which is what steganography in effect does. Rather, it is merely to make it more difficult to claim that a work is orphaned. One could then decide to photoshop the image to remove the credit anyway. But the infringement becomes considerably more blatant. That may be enough to dissuade many picture-snatchers, whether at media websites or on social networks, from taking liberties with other people's work.