Someone who is on the autistic spectrum and knows a lot of information about specific topics. They tend to prefer face to face interactions over text because they come across differently than they do in person. Examples of this include giving unwanted opinions to strangers online/twitter regarding science or medical care. Doesn't take kindly to being made fun of or being messed with. Has nothing nothing better to do than make this urban dictionary definition.
A Shackteau is a humble, weather-beaten, structurally questionable shelter located in a spectacular or highly coveted place—Wales, Jackson Hole, Sun Valley, Crested Butte, coastal Maine, the Alps—where the building itself may be worth almost nothing, but the dirt, view, access, and mythology make it absurdly valuable.
In use:
Shackteâu - We thought it was an abandoned shed until the realtor called it a rare alpine Shackteâu with unobstructed views and listed it for $2 million.