A top German court has blocked the extradition of a Turkish man accused of stealing close to $60 million in cyber attacks against credit card companies.

The U.S. government claims that Ercan Findikoglu led a hacking group and helped hack into the networks of payment processing companies, including EnStage and ElectraCard, to raise the limits on prepaid credit cards and then withdraw money, according to Sophos' Naked Security blog. The attacks reportedly took place between 2011 and 2013. Findikoglu could face 250 years, and the German court said the possible sentence was too extreme.

He was arrested at Frankfurt Airport in December 2013 and has been awaiting an extradition decision ever since.

One of the group's biggest attacks targeted the Bank of Muscat, Oman, and led to the theft of $40 million with 36,000 ATM transactions occurring within 10 hours.