Luis von Ahn at PopTech 2009

  • Luis von Ahn
  • Computer science professor, Carnegie Mellon University

Harnessing brainpower: von Ahn invented ReCaptcha, a program that uses squiggly characters that humans easily decipher but blocks spambots – and helps digitize millions of old texts. The CMU professor also makes games that use human knowledge to improve computers. Find them at .