It is your choice to befriend people or not. It does not really "do" anything besides make it easier to find that person out of the multi-thousands of members if you want to send a personal message or interact more than just on the boards. It is not like Facebook with its public intensities or anything. Most people are not worrying about other people's friends pages and, since we all have nicknames, not like you know that much about a person when you first become friends, just that you like them at the moment.