Has anybody tried unsupervised deep learning from youtube videos? YouTube has a huge amount of videos, many of which also containing various spoken languages. This would presumably provide something like the data that a "challenged" baby would experience - "challenged" meaning a baby without arms or legs (unfortunately many people are born that way). 

Would this not allow unsupervised learning in a deep learning system that has both vision and audio capabilities? The neural network would presumably learn correlations between words and images, and could perhaps even learn rudimentary language skills, all without human supervision. I believe that the individual components to do this already exist.

Has this been tried, and if not, why?
Yes, it is possible, and yes, it probably has been done before. Odds are, however, the person(s) who tried were disappointed with the results and forgot to tell others. 

The reasons they might be disappointed could be any of the following:


Took to long to train
Even when fully trained, (or appeared to be), it did not give the expected output
Too sensitive to variations in the input