Really exited to see the Whitepaper released! Have been waiting on this day since 2013 
I must admit I have a hard time getting my head around it though. So perhaps my question is already answered in the paper and I just didn't understand it...
So the Universe is split up in X shards. Each shard is a part of the network contain transaction information, right?
Now what happens if a bad actor (Bob) sets up a lot of nodes that store, say, Shard (2) of the network and by that stores all or at least the majority of that shard.
Now Bob sends a a payment to Alice in shard (3). Alice now asks a node serving Shard (2) if that transaction is valid. But as Shard(2) is controlled by Bob, can't he return false information and thus double spend transactions over and over?
I must admit I have a hard time getting my head around it though. So perhaps my question is already answered in the paper and I just didn't understand it...
So the Universe is split up in X shards. Each shard is a part of the network contain transaction information, right?
Now what happens if a bad actor (Bob) sets up a lot of nodes that store, say, Shard (2) of the network and by that stores all or at least the majority of that shard.
Now Bob sends a a payment to Alice in shard (3). Alice now asks a node serving Shard (2) if that transaction is valid. But as Shard(2) is controlled by Bob, can't he return false information and thus double spend transactions over and over?
Bob will have to send the commitment data (see white paper) along, and by checking the hashes of the merkle tree you can prove the (in)validity of any atom.