What do the strange tiny transactions executed at the same time during the ICO mean?

Question

Exploring InChain ICO smart contract transactions. Smart contract address is 0x162ac26e2f0fe036c3a3d370c118de0b6c883083

There are many tiny amount transactions executed at the same time. Like this, for example: https://etherscan.io/tx/0xb515d370fc6912a1ee88ed371035906e5c4d50f94009c52c03a4eb7b23a5c9dd

Usually all these tiny transactions are executed from the addresses that were used to deposit funds to ICO some time before. For example: https://etherscan.io/address/0xd0f0d00d85ca8237b9845d64d49098d03c3275fa

As you can see there was a transfer of 19.99 Ether at block 2516173. 5 hours later 0.00571868 Ether were sent to the same contract. Almost all the ICO transactions have the same pattern. One incoming transaction from some exchange wallet and two or more transactions to the ICO contract. And all the addresses have a balance like 0.000xxxxx Ether now.

I would like to know how is that possible that a large number of tiny transactions are executed at the same time from the large number of addresses (that belong to different people in theory)? Does it mean all the addresses are managed from one centralized point? To execute all the transactions at the same time the wallets should be unlocked simultaneously. This can be done with some APi or specialized script. Or maybe the accepting contract can execute some kind of 'delayed' transactions that were authorized several hours before by the address owner? Why all the accounts have a balance near zero now? Is it possible to send all the funds from Ethereum Wallet and leave 0.000xxx Ether using Mist or geth for an unexperienced user? I tried to do that but usually 0.01 Ether were still kept by my wallet.

Answer 1

While we may only guess here, one explanation looks very obvious:

1. Somebody got 20 ETH on his address: tx1
2. He wanted to send all this ether to InChain ICO but he cannot send exactly 20 ETH, because he has to pay transaction fee, so he sent 19.99 ETH: tx2
3. Then he realized that the amount left is still higher than fee, so he sent a bit more ether to InChain ICO: tx3
4. Now balance is less than fee, so he stoped sending

In other words, sender was just too lazy to set gas price manually, estimate fee to the Wei, and calculate transfer amount that will empty his account, so he just did this iteratively and still didn't manage to empty his account: it still has 0.00083745 ETH which is not enough to pay fee for single transfer.

Answer 2

Probably your guess is as good as mine. One option is that they are trying to fake interest in the ICO and are issuing the transactions themselves.

One way to do accomplish is to pre-sign the transactions (so you have a bunch of signed transactions) and then broadcast them at the same time. Of course they need to be signed by the correct private key. So in that sense the transactions are "delayed".