Yes, jailbreaking an Apple TV device is possible. Jailbreaking a device will give you root access to its operating system and allow you to bypass security restrictions, download unauthorized apps not available in the official App Store, and customize your device in basically any way you want to. Only do so if you really know what you're doing, though, and are aware of the risks involved. Jailbreaking your Apple TV can pose security risks since doing so will allow you to download unauthorized apps that may or may not be malicious in nature.