Earlier quoted context omitted.
The perl one liner was funny, the shell one liner was light hearted, but your node solution is just pure fanboyism and quite frankly not in line with the spirit of the two previous posts.
And.. the node.js solution doesn't do what either the Perl or shell one liners do. It doesn't tell you whether the password was found in the file. All it does is print out a SHA1 hash of a string.
$ echo linkedin | xargs node -e "var x = require('crypto').createHash('sha1').update(process.argv[1]).digest('hex'); console.log(x.substring(5));" | xargs -I {} grep {} hashes.txt
I'm surprised at the backlash to what I thought was fun code golfing. No one called me names after I posted a simple Python solution that didn't check the file. For what it's worth I've changed my LI password and I haven't bothered downloading the actual hash file.