Does using YouTube LiveStreamingAPI(LiveChatMessages) violate the Terms of Service?

Question

I try to get video's live chat, but LiveChatMessages API returns the following user's information.

• items[n].snippet.authorChannelId

YouTube Terms of Service prohibits the acquisition of information that may identify an individual.

Permissions and Restrictions

4. collect or harvest any information that might identify a person (for example, usernames), unless permitted by that person or allowed under section (3) above;

What should i do?

1. can't use LiveChatMessages API. (Who can use it?)
2. If I don't refer to snippet.authorChannelId, I can use LiveChatMessages API.
3. I don't care about anything.

Answer 1

There's nothing to worry about here: only obtaining from the API the property snippet.authorChannelId does not violate any TOS specs, since this property is nothing more than the chat poster's ID:

snippet.authorChannelId (string)

The ID of the user that authored the message. This field is only filled for the following message types:

• If the message type is textMessageEvent, the property value identifies the user that wrote the message.
• If the message type is fanFundingEvent, the property value identifies the user that funded the broadcast.
• If the message type is messageDeletedEvent, the property value identifies the moderator that deleted the message.
• If the message type is newSponsorEvent, the property value identifies the user that just became a sponsor.
• If the message type is userBannedEvent, the property value identifies the moderator that banned the user.

Having an user ID -- that is that user's ID as assigned to him/her by YouTube -- does not fall under the spec you've quoted.

You may very well use that ID for to obtain the publicly available data of the respective user (i.e. YouTube channel): just call for the Channels.list API endpoint passing to it that ID as the parameter id for to obtain (again only public) data about that channel in the form of a Channel resource.

Otherwise is good to be attentive at complying with YouTube's DTOS specifications and is quite advisable to be familiar with the content of that document.