Does a forum, Q&A, or discussion site really need to require users to create complex passwords when they register? For example, when I registered for a Stack Exchange account, the form required me to use a password that includes small and capital letters, numbers and special non-repeating characters.
I don't think that these sites are particularly security-sensitive, like a bank account, where data loss or disclosure of information can occur if it is not properly protected. They're just discussion or Q&A sites.
I find it annoying when I'm told to make such a complex password that I don't think I can remember it easily. Users end up setting their browsers to remember passwords for them, which I feel is far more dangerous than users creating a weak but easily remembered password (like
cat81) which they manually enter when asked to do so.