[Jagermonster]

robot.txt is a file at your website that tells automated web browsing systems called robots (like the ones at Wayback) whether they may or may not access the site.

Facebook seems to generally exclude robots from accessing their site, preventing the wayback machine from archiving facebook pages. Your own facebook profile would similarly not be available on the Wayback machine.

[RightField]

Interesting. Thanks for that information.