gistfile1.rb

require "open-uri"

urls = %w(
	http://pastebin.com/raw.php?i=Kc9ng18h
	http://pastebin.com/raw.php?i=vCMndK2L
	http://pastebin.com/raw.php?i=JdQkuYwG
	http://pastebin.com/raw.php?i=fw43srjY
)

passwords = Hash.new{|h, k| h[k] = Array.new}
urls.each do |url|
	open(url).each_line do |line|
		username, password = line.chomp.split(/:/, 2)
		passwords[username] << password
	end
end

lookfor = Regexp.new(ARGV.map{|s| Regexp.escape(s)}.join('|'), Regexp::IGNORECASE)
passwords.keys.select{|username| username =~ lookfor}.each do |username|
	puts "#{username}:#{passwords[username].uniq.join(':')}"
end

open(url)のあたりは https://gist.github.com/2641537 を参考にさせていただきました

速度重視型 https://gist.github.com/2642013