New Zealand Labour Party using SMS to chat with youth

A new website launched by the New Zealand Labour Party promotes chats with MPs, including SMS options. The site publishes a schedule with next appearances.

To use the CHAT BY TXT feature for free, all you need to do is type CHAT before your question and send it to 5227 [LABR].

The caveat is this part of the conditions: "By giving us your contacts, you'll be registering to know everything thats going on. We'll keep you informed by TXT or e-mail of news, chats, and features".

I wonder if they assume that participating in the chat is implicit authorisation to be included in the mailing (SMS mailing) list.