The ThinkUp API: UserNotFoundException - nilakshdas/ThinkUp GitHub Wiki
This exception is thrown when you have queried for a user that does not exist in ThinkUp's database.
Example
webapp/api/v1/post.php?type=user_posts&username=samwhat
{
"error":{
"type":"UserNotFoundException",
"message":"The user that you specified could not be found in our database."
}
}