I'm a dirty rotten thief. Somebody somewhere on SF3 Node 1 has their ender chest setup on the default 3 white and it is not secured. I realized this as I was hooking an ender chest up to my RS system. Before I could configure the chest I noticed some odd items in my system. Sorry to whoever I stole from. If you can tell me what was in the chest I'll be happy to return the stuff. In the future you may want to move your chest off the default channel or at least put a diamond on it to secure it.
To be fair, I think that, if you use a public channel, then you are responsible for the item loss. There is almost no way to track thievery from chests that aren't privated, at least not to my knowledge. So with that said, you are definitely a very honorable individual to publicly post about this. Usually, people would simply shrug it off and say, "shucks".
Props to you. Sadly there is no way to track this server side as @mrminesheeps pointed out. I do hope that the person who those items belonged to gets them back. That being said it is a good learning experience for that person to personalize their chests