MasterCard and Visa have moved to prevent virtual private network (VPN) providers from accepting card payments, according to Swedish firm Payson. However, Visa Europe insists it has not been involved "in this matter in any way".

The recent revelations made by whistleblower Edward Snowden about widespread Internet surveillance carried out by the US National Security Agency (NSA), have seen VPNs become increasingly popular as a way to keep users' activities private.

In an e-mail to VPN provider customers, obtained by TorrentFreak, Swedish payment services provider Payson says that Visa and MasterCard changed their policies earlier this week.

Says the e-mail: "Payson has restrictions against anonymisation (including VPN services). As a result Payson can unfortunately no longer give your customers the option to finance payments via their cards (Visa or MasterCard)."

However, in a statement to Finextra, Visa Europe says: "Visa Europe has not been involved in this matter in any way, and has not made any such stipulations to Payson or to any other organisation."

It appears that the issue may be down to Payson's acquiring bank, rather than MasterCard and Visa.

Pirate Bay co-founder Peter Sunde, who launched the iPredator told TorrentFreak that the decison means that US firms are forcing non-US companies to refuse people the right to privacy.

Payson says firms can still accept payments via bank transfers while Sunde points to bitcoin as an alternative to the card giants.

Meanwhile, in a separate, contrasting development, WikiLeaks says that MasterCard has finally ended its two and a half year blockade on the whistleblowing site.

In late 2010, payments firms including MasterCard, Visa and PayPal began blocking donations to WikiLeaks in response to its decision to start publishing US State Department cables.

But earlier this year Iceland's Supreme Court ordered local card acquiring outfit Valitor to start processing payments for whistleblowing Web site WikiLeaks within 15 days or face daily fines of nearly $7000.

WikiLeaks now says that in a letter from Valitor's lawyers, the firm revealed that "MasterCard made clear to Valitor that it no longer desires to blockade WikiLeaks".