Coin base recently prohibited me from making a bitcoin request with a pop up saying I already made too many requests. I had maybe 3 requests that day. Any one else see this? What is the purpose of limiting requests?
Take a look: https://developers.coinbase.com/api/v2#rate-limiting
The limit is quite high, it is really strange you received an error response. I suggest you to contact their support, and meanwhile changing your API key (if you're using one) could be a good idea.