They apparently went through an open gate, and ran into Justin while he was hanging out with his friends by the pool.
Though he didn't call the police, he did confiscate their cell phones — which he gave back to them a few days later, when they "sheepishly" returned.
Of course, that's pretty scary! Since he's so passionate about his Beliebers, we knew he probably wouldn't hold it against them, but we're kind of surprised that he tried to teach them a lesson.
It sounds like they didn't do anything too crazy, though. They just took a pic of themselves with a sign reading, "We Love You, Justin Bieber." Still, that's definitely not cool to break into his home!
Can you believe Beliebers broke into Justin's house? How would you react? Tell us in the comments!