I am in the process of making some site structural changes. In the cPanel Error Log this morning, I noticed three attempts from an IP address in the Ukraine. They were looking for: .../google_sitemap.xml, .../sitemap.xml, and .../sitemap/. I presume it's not Google, and is someone sniffing around for a way to get in. Anyway, someone finding a standard sitemap for your site is going to get a nice layout of the place (minus anything you excluded). Does anyone know if there are intrusion methods that make use of this knowledge? Should I be concerned enough to not  put out standard format sitemaps? Or, as long as I keep anything sensitive out of the sitemap, no harm done?

If nothing else, this should be a wakeup call to be careful about what goes into your sitemaps, and to exclude sensitive areas from automatic sitemap generators, that you don't want indexed. Check your sitemaps, especially if they're generated by some program, to make sure you're excluding anything you don't want indexed -- or broken into.

I know I've been playing with the google sitemap generator on a VPS, and if you are not careful, it will index pretty much everything.
I had to set it up to just index .html and .pdf files.