Labradoodles can be protective when they need to be.
Some Labradoodles will sometimes be shy around strangers and may stay away from them though so it depends on the Labradoodle.
But most Labradoodles I've known where very protective when they came up against strangers and they can detect when someone is bad as well.
While Labradoodles can be very protective at times they are also very gentle dogs and smart and are also fun loving, affectionate, athletic, graceful water lovers, and good watchdogs.
They will usually alert you to someone coming up to your house as well and if needed they will bark and growl to get rid of the threat.