Some Unix purists dislike these safety features, but I prefer to protect myself against the inevitable lapses of concentration that occur during a long programming session. Apply All Recommended Updates For convenience most of us install Linux from CD-ROMs. This has security implications. The open-source community is quick to find, announce and fix security holes that are found in programs. All distributions have an announcement mailing list you can subscribe to, or a website page listing security updates.
All distributions also maintain web or ftp sites where updates are stored.
If you're not using Red Hat, learn where these announcement lists are for your particular distribution and become a frequent flyer. Download and apply all security fixes as they're announced. Update any part of your system that your vendor recommends. The majority of the cracked sites on the Internet are those that have been lax about security updates. Don't be naive, or lazy, about security.