Your legal knowledge has left me speachless.

Amazon has very generic trademarks on the word echo. Podcasts are a recorded format meant for playback that provides commentary on different categories. Amazon definitely holds trademarks on these types of areas. That said, I'm not a lawyer so I can't speak to how much issue the overlap would cause but regardless Amazon has billions of dollars and could walk all over anyone they want so I'm pretty sure if this got bigger and they took issue with the use of the name Echo they could cause a lot of hell.