As requested

 is a holotape that is found in the Hollowed-Out Rock south of Megaton, together with a Sniper Rifle and other useful items.


 * The "S" mentioned might be the character Sam Warrick, who roams the Capital Wasteland with a Sniper Rifle, usually hunting Wastelanders. This may also refer to the sniper guarding Megaton, Stockholm.


 * The sender who is named "E" is most likely Edward the Cannibal from the Fallout 3 Diaries.


 * This could be a reference to the "hollowed out stump" behind Thirsk, from The Elder Scrolls: Morrowind's expansion, "Bloodmoon". that says nearly the same thing.