Guero said:
It's a tough call, legislation isn't anywhere near as fast as current internet/data technology so technically certain things like looking up how to convert an M4/AR15 to fully automatic aren't illegal...
But as the recent AOL fugg up demonstrates, you aren't very hidden when it comes to searching for stuff on the net.
http://news.com.com/AOLs+disturbing+glimpse+into+users+lives/2100-1030_3-6103098.html
And AOL User 17556639 should really make you think about issues related to online searches and legality...
http://plentyoffish.wordpress.com/2006/08/07/aol-search-data-shows-users-planning-to-commit-murder/