Download captions from any video #548

Hi,

Many third party libraries allow people to download captions using their service, however the YouTube Data API v3 doesn't. I can't find any video where i can download captions, apart from my own. This means, it would infact be illegal for me to use those services, and create a service that allows people interact with those transcripts.

Is there anyway around this or is it impossible to create any service based on public youtube videos and their transcripts?

Thanks,

Viraj