[Modin]

Yeah, there's many ways to hack a board, either by a board vulnerability (which I haven't seen any for vb3), a security vulnerability like improper passwords, improperly set permissions etc, or if the host is running vulnerable software like older versions of apache, mysql, php, has improper security permission there too, etc... (got ya scared yet?) In the later case if your host has stuff improperly set up then there's nothing you can really do to protect yourself, though with the suggestions above by others you can be sure it wasn't your own fault

They reason they hack is usually for giggles, I've known a couple of these people and they get their kicks by seeing that "404 error". The odd time it's for revenge, but rarely.

Personally, including the other's suggestions, just keep a recent backup of your site on a different pc, I usually backup every couple days or so, so worst case I've lost a couple days of posts...