ATNDから参加者のTwitterアカウントを抜き出すRubyスクリプト ref: http://qiita.com/items/2566

export_atnd2twit.rb

#!/usr/bin/env ruby

require 'open-uri'
require 'json'

if ARGV.first.nil?
  puts <<EOF
    USAGE: export_atnd2twit.rb [ATND EVENT ID]
    e.g. ruby export_atnd2twit.rb 24700
    # http://atnd.org/events/24700

    NOTE: List Limit members 500!
EOF
  exit 1
end

atnd_id = ARGV.first
url = "http://api.atnd.org/events/users/?format=json&event_id=#{atnd_id}"

json = open(url).read
result = JSON.parse(json)

members = result['events'].first['users']

puts members.map{|member| member["twitter_id"] if member["status"] == 1}.compact

file1.txt

ruby export_atnd2twit.rb 24700|xargs ruby import_twilist.rb