Friend Agenda is a fictional community website which has appeared in various episodes of CSI: Las Vegas and CSI: Cyber.
The details about the website are unknown, but appears to be similar in concept and design to real-life website Facebook. It has appeared on CSI several times, in Fallen Idols, Goodbye and Good Luck, Turn, Turn, Turn , Internal Combustion, Say Uncle , Man Up, Trends with Benefits, Ghosts of the Past and Kitty. In most circumstances, it yielded evidence which helped solve the case, though not in the case of the latter. CSI's version of Facebook, without saying Facebook. They layout of the pages, etc are nearly identical.
No longer fictional. There is a "Friend Agenda" app in the Apple Store.