Andreas Antonopolous is chief security officer at Blockchain.info, a popular Bitcoin wallet service, and he tells CoinDesk that numerous Bitcoin exchanges are experiencing a "massive and concerted" denial of service attack right now.

This is a type of attack on one's digital real estate in which nefarious hackers bombard servers with junk requests over and over until they become useless. It's akin to filling a glass of water until it overflows.

In Antonopolous' words: "As [Bitcoin] transactions are being created, malformed/parallel transactions are also being created so as to create a fog of confusion over the entire network, which then affects almost every single implementation out there."

In other (simpler) words: this attack may cause Bitcoin to behave weirdly.

He added that no money has actually been lost, as exchanges halt withdrawals as needed in order to keep everything synchronized. One exchange affected by the attack, Bitstamp, sent an email to its customers to that effect.

Antonopolous predicts things will be operating normally in between one and three days.

The attacks come on the heels of popular Bitcoin exchange Mt. Gox having to halt a number of its exchanges as customers withdraw their money and even go so far as to protest outside the company's offices in Japan. Bitcoin's price has taken a big dip since.

Bitcoin is currently sitting at ~$670.