In the days of paper memos, a BCC or "Blind Carbon Copy" would most likely not come back to haunt you.
Now, however, you can 'bcc' someone and, if the recipient doesn't realize it, she can 'reply all' and then reveal herself.
That happened to me.
No, I didn't send the email w/the bcc, but someone (who later revealed herself) was the bcc on an email to me.
And, when I found out, I was pretty irritated. Angered. Upset. Betrayed.
It automatically lowered the trust I had for the person who sent the email to me.
Comes back to the topic of anonymity and anonymous comments.
Something to think about before you start bcc'ing others....