Sony employees have acknowledged a campaign aimed at convincing the company not to restrict used PlayStation 4 games.

The issue of limiting second hand game sales was reignited last week when Microsoft mentioned plans to regulate their use on Xbox One. Then, over the weekend, GameTrailers' Geoff Keighley hinted that Sony may still potentially follow suit.

"Microsoft is getting beaten up a lot on it," Keighley explained. "Sony, I think, has been seen as this kind of white knight so far that's not going to restrict used games. Based on some of the things I'm hearing, I don't think that's entirely true, because I can't see publishers allowing one system to do one thing and one do another."

From one Pope to another - Shuhei Yoshida has remained quiet on the issue.

Indeed, EA recently cancelled its Online Pass solution, designed as a way of recouping costs from second hand game sales. EA didn't mention only culling the scheme from Xbox One, where a used game tax appears likely.

In response to this latest uncertainty, NeoGAF users began circulating the #PS4NoDRM and #PS4USEDGAMES hashtags on Twitter yesterday and targeted messages at high profile Sony employees.

"This is why I love PlayStation fans - the passion bucket overflows," Sony's head of hardware marketing John Koller wrote in response to the campaign.

"Humbled by the outpouring of passionate PlayStation fans and their willingness to talk to us directly," said SCEA producer Nick Accordino. "Please know that we hear you. <3"

"I love passionate #PlayStation Fans!!", Sony Worldwide Studios product boss Scott Rohde added.

Sony has yet to mention the campaign officially, however, and there's been no word from its top target - Shuhei Yoshida, president of SCE Worldwide Studios.

"Used games can play on PS4," Yoshida told Eurogamer in February, back at the PlayStation 4 unveiling.

But Sony's position on the matter has become less clear in the wake of Microsoft's confused attempts to explain the issue. Used games can play on Xbox One, too, although with restrictions.

Nintendo may be the only company not to restrict second hand games - good news for Robin Williams.

Microsoft exec Phil Harrison went out of his way to try and clarify game ownership and second-hand sales queries with Eurogamer at the Xbox One announcement event last week, but subsequent updates from Microsoft mouthpiece Larry "Major Nelson" Hyrb have only made the company look like it still hasn't made up its mind.

"The ability to trade in and resell games is important to gamers and to Xbox," Hyrb wrote over the weekend. "Xbox One is designed to support the trade in and resale of games. Reports about our policies for trade in and resale are inaccurate and incomplete. We will disclose more information in the near future."

An open letter to Sony, penned by one NeoGAF user, explains the fan campaign in more detail.

"You might be wondering what the above hashtags really mean," the letter states. "Simply put, they are requesting you to keep things on PS4 as they are on PS3, when it comes to physical disc rights and second hand discs.

"Microsoft has ignited a firestorm in announcing a strategy for Xbox One that would see consumers unable to lend a disc to friends, unable to privately sell or swap a disc, and only able to trade discs at pre-approved retail [stores].

"We believe this is a big mistake, and we'd like you not to share in it."