Pseudonymous bitcoin miner by the name of artforz was able to unfairly benefit from mining over 1000 blocks quickly by taking advantage of a flaw in the timestamp server of the bitcoin network in 2010

Centralized service called the timestamp server is used to confirm the time that blocks are mined. In order to appear as though he discovered mined blocks sooner than other people artforz manipulated the timestamps on them by taking use of a flaw in the timestamp server. Because of this trickery artforz was able to mine blocks more quickly than other miners giving him an unfair edge not to mention he used 24 combined ( radeon 5970s + radeon 5770s + radeon 4870 ) gpus in his setup It was quickly corrected. But before the exploit was fixed ( in few weeks ) artforz was able to mine over a 1000 blocks and per block reward was 50 btc. At the time these blocks had a value of $15 so the value of over $1.3b at the time of writing this. Artforz was able to preserve them.

The bitcoin network had a significant security flaw that was exploited by the timestamp server attack. It made clear the necessity for a timestamping service that is more decentralized like the bitcoin time protocol ( btp ) a decentralized timestamping service. The btp is intended to guard against future exploits like the timestamp server attack.

Timestamp server attack hack was an important development of bitcoin. It demonstrated that the bitcoin network is not impervious to security flaws. The bitcoin community was able to quickly remedy the flaw and stop additional attacks though.

On bitcointalk you can see him explaining a similar exploit himself.

If you would have been in artforz's shoes would you have done the same? Honestly I would have been very tempted too!