I believe it is the first option, because machine translation is famously inaccurate. If the original poster speaks your language, they will understand you better than if you had translated it. If they do not speak your language, they have access to the same online translation tools you do, and they can translate it themselves.

I have just met a French speaker who is adamant that replying in a different language is ethnocentric, which prompted the poll.

I would love to hear other people's thoughts on this.