The singer was performing at the Tacoma Dome in Washington yesterday (October 9) as part of his 'Believe' tour when the incident occurred.
"Sucks when u take personal footage and people don't respect your privacy," Bieber tweeted.
"Yesterday during the show me and my tour manager Josh had some stuff stolen. Really sucks. People should respect other's property.
"I had a lot of personal footage on that computer and camera and that is what bothers me the most. #lame #norespect."
Bieber was recently forced to apologise to fans after vomiting on stage in Glendale, Arizona.
The 18-year-old was performing 'Out of Town Girl' when he had to run off stage to compose himself.
Watch Justin Bieber's video for 'As Long As You Love' below: