Fortnite players are reporting that they are seeing Xbox gamers in PS4 games, suggesting that cross-platform play has been surreptitiously - or perhaps accidentally - enabled.
One PS4-owning Reddit user reported this week that they spotted a player's name with a space in it, which is not allowed by PlayStation Network. However, that gamertag did appear to be in use on Xbox Live. Perhaps he was playing on PC? Apparently not.
Fans of the game were then able to identify other examples, including a father-and-son team playing together on Xbox One and PS4 respectively.
It's well known that the two main consoles are happy to engage in cross-platform play with PC and potentially other formats under the right circumstances, but up to now we've never seen players invited to play across the all-important Sony/Microsoft border.
There is often debate about who is responsible for this, with a lot of fingers pointed at Sony.
There's no confirmation from any of the parties involved that this feature is in Fortnite, let alone officially, but the idea that it could work and isn't a huge issue is likely to fuel continued frustration that the two platform holders can't find a solution to allow it.