Whisper, the social networking app that lets users post anonymous messages, may have been tracking its users' locations - even those users who have opted out of the service's geolocation features. According to an in-depth report by The Guardian, the service is also accused of closely monitoring the activity of noteworthy individuals. While the company denies these allegations, it is an excellent example of how “anonymous” is a relative term. Learn more about other “temporary” apps that are popular today in the article by Common Sense Media entitled Snapchat and 6 Other Messaging Apps That Let Teens Share (Iffy) Secrets.