Connect to my own Minecraft server with cracked?

In server.properties file set online-mode=false

Then there's no checking with minecraft.net to see if an account is valid or has a valid login. And certain files to allow or disallow things by player name, like banned-players.txt, white-list.txt, or ops.txt, would not be very effective against other players, because a player could change their name to someone allowed on, or even to the name of an op (admin).