Yes, it is, for a number of reasons. For example, if a hacker got into the AnswerBank then, rather than defacing the website, they could (quietly, surreptitiously) change the account details in the post, and forever more the loyal members could pay the hacker rather than AnswerBank, who may not even knew they had been sent the details.
Still, if that happened, that hacker could just add a new post with the details, e.g. as AB Editor. It would not need to change an existing post. This is one reason why you should not "pay into a bank account based on an open forum", or for that matter any open website.