We've definitely had the "pit bull" comments at PetSmart about Diesel, but it's hard to really be afraid of him when he has that big goofy grin on his face, so most people will usually approach and ask to pet him. When I take him for walks people will cross the street to avoid walking near him. Sometimes older men will talk to us and comment about how pretty he is... and their wives avoid eye contact and try to walk away. It's weird.
On the other hand, should anyone take a step onto Diesel's driveway or into his house, he goes into full watch dog mode. We were having furniture delivered one day when it was just him and me, and he stayed between me and the furniture guys every second. I told him it was okay patted his rump, which I guess meant I had it under control, and he became a big scardy dog and ran out back and watched from the window! He'll be protective when necessary, but he's a weeny at heart!
What's funny is that my mom is kind of nervous around strangers, so if she's walking him or if she's home when the exterminator comes, Diesel will guard her no matter what. It's as if he senses her fear and knows that it's his job to protect her.
But I'm pretty sure that if someone were to come into the house while no one was home, he'd hide behind the couch, and if they were nice, he would ask them to get him a cookie.