As a photojournalist, I tell stories with images. It's a simple concept. I work very hard, and make many personal sacrifices, to tell these stories. They have often been published right here in the Guardian. One of the things I love most about photography is that it transcends language. A written story has to be translated many times to get a truly global reach, but photographs are instantly understood.

I've watched the growth of online news and social media with great excitement, but the internet has its drawbacks. For photographers, the biggest problem is the ease with which anyone can steal pictures. Whether I post an image on Facebook for my close family and friends to see, upload a photo story to my website as part of my professional portfolio, or tweet a picture from a news story to my followers, the outcome is the same: anyone can save, copy, share, re-post, or alter it, and there is nothing I can do about it. Nothing!

There is a widespread belief online that once a photograph is posted then anyone is free to use it. This is not the case, just as it is not the case with music, or movies, or any other intellectual property. The thing that frustrates me most of all is finding my photographs used online without any mention of my name. I've worked in Afghanistan for years, and have taken great risks to produce some of my work, and the very least I expect is to be acknowledged as the author of that work. The music and film industry is fighting hard to change people's perceptions about piracy, but the battle for photography hasn't started.

I am firing the first shot and my weapon is Marksta, a little app that was born out of my frustration with online copyright infringement. Marksta allows users to watermark their photography, simply and quickly, with text (for example Twitter name or website address), a logo, or the copyright symbol © directly from an iPhone, before sharing pictures to Facebook, Twitter, Instagram and Tumblr. Whatever the photograph, a quick snap or the most treasured picture, it deserve to be recognised and protected.

I know watermarked images have in the past been seen as unacceptable by newspapers and magazines, but losing my entire career is just as unacceptable to me. I'm not talking about crude and ugly watermarks, splashed across the centre of a picture. A simple ©John D McHugh placed carefully in the corner of the image or better yet on a border so the image is unaffected, will suffice. If somebody wants to use the image commercially without the watermark, then they know exactly who to contact to arrange permission and payment. If the picture is uploaded to social media and becomes a viral hit then Marksta will ensure the photographer gets the credit.
 
With the British government threatening to erode the rights of photographers with new copyright laws, and the risk that unidentified photographs can be deemed "orphan works" and used without payment or credit, it is more important than ever that photographers (professional and amateur) protect their work.

There are also very real concerns that social media sites intend to take users' photographs for their own promotion and profit with no regard for intellectual property rights. Instagram has already been embroiled in controversy over a proposed change in its terms & conditions, which was widely interpreted as a rights grab.

Marksta is designed as a simple tool to help photographers safeguard their creations. Launched on 3 January, it is already proving very popular. Within 24 hours the app had been downloaded almost 5,500 times, in less than a week it was in the Apple Store Top 50 in the photo and video Category and on 6 January ABC News named Marksta "App of the Week."

Marksta is available in the App Store and more information can be found on Facebook