I should also follow up with a technique that might be of interest to programmers. Some Minecraft blocks have textures that appear rotated in one of four ways. Turns out this rotation is pseudorandom, the rotation number is a result of seeding Java's rand.nextLong() with the (x,y,z) coordinate of that block.[0] This has been used for "malicious" purposes such as finding the location of a base from a single screenshot, which can lead to its destruction on anarchy servers. The author of the linked video used a CUDA search to find the location of a wall of netherrack.