$BTC Back in 2011, Stefan Thomas was one of the few cryptocurrency experts in the world. The only requirement this Swiss programmer asked for was that the payment be made in bitcoins. In total, he received 7,002 bitcoins for his work, which at that time was worth less than a dollar each.

He made three backups of them but accidentally deleted two.

The third backup is stored on a USB drive or 'cold wallet' from IronKey that automatically erases its contents after 10 failed attempts to enter the correct password. The problem is that Stefan Thomas lost the paper where he wrote down the key and, so far, has exhausted eight opportunities. This means he only has two left to guess correctly and access the more than 700 million euros in bitcoins stored inside.