Linux is really only as secure as you make it. No distro is completely secure out of the box. If you want secure out of the box you may want to look into OpenBSD . Real men upload their data to an FTP site and have everyone else mirror it. I'm curious if jimbix can offer examples of how Slackware runs the same stuff 'in a more secure way' than any other distro.
Defaults offer only a balance of performance and stability.
This really is NOT the whole story. You'll need to learn to decipher your logs if you want to know if you're really secure and perform tons of other security related tests.