Eustass literally attacked civilians because they laughed at him.
He said so, quote;
"You know on the path we've been traveling up until now... Saying a thing like that (finding One Piece) would just get you laughed at. Although... I slaughtered anyone and everyone who had the nerve to laugh at me...!!"
I repeat, Eustass literally attacked civilians because they mocked and laughed at him. He doesn't even specifically say what they were laughing at.
Shakky says in chapter 498 :
"The reason why Kid has a higher bounty than you (Luffy) is because they cause a huge amount of damage to ordinary citizens..."
.
.
What made ordinary civilians laugh so bad at Eustass Kid that made it ok to risk their lives for
.
.
^ Notice anything yet?
^ How about now?
... 'Snorkel Mask' Captain Kid
The dude most likely looked like a right goof whenever he wore them properly.










