Principle 3: Employee-owned devices that contain unique, relevant ESI should be considered sources for discovery.
We would add the word “always” before “should be” in that sentence. BYOD devices may not be discoverable in every case, but they should at least be considered in every case. As we discussed in the post Busting the Myths Associated with Mobile Device Discovery, text messages, files, photos, videos, phone logs, phone notes files, phone voice memos and geolocation data is all data that is typically only located on the mobile device and is often discoverable. If you’re not considering that data as a potential source of unique, relevant data in discovery, you’re making a mistake.