Got asked by someone unfamilar with Linux and BSDS how people could tell "genuine" copies, and apparently not aware the difference between a commercial OS and a GPL/BSD licensed OS. Even after telling the person what the GPL meant, they still could not figure out the concept of not paying for an OS... so I recommended they go with a commercial version of Linux, so they could pay for support...
So here goes... a shell script for a genuine check:
echo "Please wait while validating if this copy of Linux is genuine."
uname -o|grep -i Linux>/dev/null
if [ "$?" -ne "0" ]; then
echo "I am sorry, this is not a Genuine Linux install."
echo "This copy of Linux is genuine!"