Back in the Myspace era, I was bored and created an easy encoder-decoder for people to play with. It worked with Twitter, Facebook and Myspace (cut-paste your encoded text) because it only used basic characters. As you can't see in this animation, I later added random spaces and punctuation to the encoded text so that theoretically it would be harder for social networks to detect and block. The text was encoded in Javascript as you typed, which I thought was cool :-)

You can see it here as a GIF animation http://pjbrunet.com/friends-secret-messages.gif The decoder was just as easy, another pink box under the encoder. Obviously a pro could crack the code but that wasn't the point.

It was free. I advertised it to hundreds of thousands of people at the top of my blog which was 99% social media users and many of them were interested in privacy related topics as I could see from the Google queries. Looking at the CTR on that banner (asking people to try it) I concluded nobody cared. I was obviously targeting people who weren't tech savvy. I had some friends try it, they said they felt like James Bond ;-) That particular app had no traction, but my "pipe letter generator" did much better.

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