Many of these agencies maintain large facilities to serve their core purposes and have to provide security for their facilities.
Little in this report is anywhere as alarming as the reports authors would like to make it out to be. OpenTheBooks.com seems to take the view that all government spending is wasteful, and by describing it out of context seeks to present it as abuse. For instance they present research grants to Ivy League schools as government subsidy of those schools [1] and The US Government employing a lot of lawyers as somehow suspect [2].
[1] http://www.openthebooks.com/openthebooks_oversight_report_%E...
[2] http://www.openthebooks.com/openthebooks_snapshot_oversight_...