Yes, I have removed all the dataline components in postbit_attachment and attachmentbit tempates when I saw the component in my google search results. This is not good for seo.
I can understand that a dateline can be good once an attachment would be updated. But in this case, the attachment should get a new id. And even if not (which is not possible due to the auto-increase mysql configuration), only in this case an additional dateline would do.
Improvement request to remove the component (everyone feel free to vote):
http://tracker.vbulletin.com/browse/VBIV-12474