The Tinker Tailor Soldier Spy star is dad to two boys and Oldman has witnessed one of the youngsters logging on to the web on his cell phone to stream a blockbuster - and he's less than impressed with the boom in home viewing.
He tells Total Film magazine, ""Technology has changed, that's for sure. My kids, one of my boys anyway, can watch a whole movie on an iPhone. Now to me, that is a mortal sin! How could you do that?
""He doesn't know any better though. He's 12. He's of that generation where that's the norm and it's not unusual for him to do that. But I find it shocking. I think that's sad.""
Oldman isn't the only one complaining about viewers streaming films instead of heading to the cinema - director David Lynch and actor Nicolas Cage have also spoken out against the practice in recent weeks.