IBU non zealously concerns to any live streaming. Yes, IBU sold broadcast's rights to lot of abroad channels, but also they provide a free opportunity to watch biathlon online. Here is a list of links, where you can watch biathlon live.
Don't forget about biathlon live-timing, very helpful thing during the sprint or individual race, or when your favorite biathlete in the down of peloton.
All kind of competitions (sprint, pursuit, mass-start, relay and individual race) in all 9 events world cup - Polljuka (Slovenia), Hochfilzen (Austria), Nove Mesto (Czech), Oberhof and Ruhpolding (Germany), Antholz (Italy), Canmore (Canada), Salt Lake City (USA) and Holmenkollen (Norway).
Also you can watch online world and european championship in Oestersund and Minsk.