A leak of WhatsApp data could mean that 500 million people's up-to-date phone numbers are being sold online for as little as $2,000.

The leaked data reportedly covers active WhatsApp users across multiple countries totaling almost 500 million people. A massive number of those are in Egypt, with 45 million phone numbers leaked. 35 million Italian members and 29 million Saudi Arabian numbers have also reportedly found their way onto the list. 11.5 million numbers were from the United Kingdom, while 32 million originated from the United States.

The data is reportedly being offered for sale on a "well-known hacking community forum" with subsets selling for surprisingly little. The seller will reportedly accept $7,000 for the phone numbers of WhatsApp users in the United States, while the UK is worth $2,500. German users can be bought for $2,000.

How these numbers were obtained isn't clear, but WhatsApp says that there is no evidence that it was hacked. However, Cybernews has confirmed that at least some of the numbers are real WhatsApp accounts, suggesting that the data is legitimate, regardless of how it was attained. The person selling the numbers simply said that they "used their strategy".

Phone numbers are often bought and then used by attackers who try to coax people into giving them money via one means or another and for that reason, it can be wise not to answer phone calls from numbers you don't know. That has its own problems of course, and with phone numbers so easy to spoof it isn't a fool-proof way to protect yourself, either.