Ikea has warned people that they must stop holding unauthorised sleepovers in its stores, or face being prosecuted as trespassers.
Earlier this year, two Belgian teenagers hid in a wardrobe in a store and then spent the night on the beds there, posting a video of the prank online that's been viewed millions of times.
Since then, around ten other groups have followed suit, in the UK, the US, Japan and elsewhere.
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But the legal threat comes after two 14-year-old girls hid in a wardrobe in Jonkoping, Sweden to stay in the store all night.
According to the Sydsvenskan newspaper, the teenagers weren't charged on this occasion, with the firm choosing to have a quiet word with their parents instead.
But the firm says that it has reported two 15-year-olds to police for a similar prank, and warns that it won't necessarily be lenient in future.
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"We appreciate that people are interested in Ikea and want to create fun experiences," a spokesperson tells the BBC. "However, the safety and security of our co-workers and customers is our highest priority and that's why we do not allow sleepovers in our stores."
It's not the first time that the Swedish chain has had trouble with customer pranks. Last year, it was forced to warn customers off playing hide and seek in its stores after 19,000 people signed up for a game in an Amsterdam store.
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And it may now find that the pranksters have moved on. Last month, two students held a similar secret sleepover at Manchester United's Old Trafford Stadium; they've done the same on a school bus, at M&M's World, Toys R Us and McDonalds.
They - and other people - have pulled the stunt at zoos, Starbucks and shopping centres. You can check out their exploits - and make suggestions for future sleepovers - here.