http://www.cnn.com/2014/02/24/world/venezuela-ukraine-protests-apps/ From Kiev to Caracas, protesters are taking their indignation to a walkie-talkie app, but some may be running into government roadblocks. Zello allows smartphone users to send short voice messages from person to person or to a limited group of people. Some Ukrainians and Venezuelans have been using the app to organize their protests. Broadcasting a message to the world on social networks like Twitter is not always ideal for many people in chaotic situations. Apps like Zello and WhatsApp facilitate private, peer-to-peer digital messaging. Facebook's $19 billion plan to purchase WhatsApp underscores the need that more than 450 million users have to send messages that aren't broadcast for everyone to see.What $19 billion can get you Zello, which was founded in Russia and is now based in Texas, has been one of the most downloaded apps in Ukraine and Venezuela, but late last week, Venezuelans began complaining that the app stopped working inside the country -- just one of the many apps and social networks that Venezuelans say have been blocked over the past weeks since protests began.