Until the torrent archive file be available for DEFCON22 run the below bashfu to download all ppt/pdfs:
wget https://www.defcon.org/html/links/dc-archives/dc-22-archive.html --no-check-certificate | grep dc-22-presentations dc-22-archive.html | awk -F "href=\"" '{print $2}'| awk -F "\"" '{print $1}' | sed 's/\.\.//g' | sed 's/\/\//https:\/\/www.defcon.org/g' | xargs wget
by 
As no giveaway DVD with the consolidated ppt/pdf materials from BlackHat’s US 2014 briefings was shared during the start (nor the end of the event), you will have to download the presentations by yourself one by one, to speed up a bit the process you may use the below bashfu:
for i in wget https://www.blackhat.com/us-14/archives.html && grep "../docs" archives.html | sed 's/\.\.//g' |awk -F "\"" '{print "http://www.blackhat.com"$4}'; do wget $i;done
by Bash script to look for system users’ files that comply with predefined specific criteria. look.for.files.shby