Because you don’t already spend enough time on Facebook. Yesterday the site, host to more than 69 million active users, unveiled Facebook Chat. Like Google Talk, the application is embedded into the site’s interface, but unlike Google’s version, there’s no need to send chat requests; everyone on your Friends list will show up as available to talk if they’re online. Like other Facebook apps, however, it’s only useful if your other friends have it. Much has been made of the threat to AOL Instant Messenger, the country’s largest chat client, but it seems like AIM’s influence diminished back when Google Talk went mainstream. Certainly, I don’t expect many twenty-somethings like me to choose Facebook over Google Talk when it comes to sneaking in personal conversations at work. But for college students, for whom the site was designed in the first place, it makes sense. If this catches on, I’ll be curious to see if it changes the way already-self-absorbed teenagers relate to each other. It’d be awesome if people would stop posting personal messages as public wall posts. Ditto for poking, but that’s more for people who want to flirt ineptly or say hi without actually having a conversation. Most of all, this is going to bring Facebook stalking to a whole new level. Think about it: If I know you’re online, I know you’ve seen the photos I tagged of you from last weekend, I know you read the message I sent two days ago, and I’m dead certain that you’re ignoring my poke. With Facebook Chat, live conversations may or may not happen, but your anonymity, as it were, will virtually disappear.