A drive-by post is one where the original poster ...
a) Posts a link with no relevant commentary of his own, or..
b) Simply cuts & pastes from another source without commenting.
Such a post as the above invites users to a link offsite with unknown content. It could be an Ad for a non-firearms releated business or some funny video. Or a site that gives your PC a virus/trojan etc.
If you cut & paste some or all of an article, you should provide a link to the original. You should also add your comments or opinion and attempt to direct the conversation towards a specific gun-related