Quote from: grau on July 12, 2015, 07:41:46 AM

- further spend attempts will not be broadcasted by a node after one of the attempts is included into the mempool

Wrong. Some clients (BitcoinXT?) broadcast conflicting txs.

Quote from: johoe on July 12, 2015, 03:09:39 PM

There are currently still > 5 BTC in the 100 most spammed addresses. Cleaning them up takes about 70 MB.

1185868 utxo (11.85868000 btc) as for block #365041 according to my set of compromised private keys
(some addresses are compressed, some uncompressed)

Quote from: johoe on July 12, 2015, 03:09:39 PM

There were several suggestion to penalize outputs over inputs when computing the required fee but AFAIK it was never done in the standard bitcoin client.

Miners think about their profits.
We can not force miners to include "normal" transactions and reject "faucet/spam" transactions, because it is economically unreasonable for them