For the first time since I started tracking this particular parameter six months ago, I had a visiting browser tagged as a "grabber" in my logs. The grabber was wget. I know it's just once among thousands of visits, but I'm a little paranoid of my content getting grabbed and diluting my serps. Should I do anything about it?
May be a scraper or something else but you should block them via .htaccess either way: RewriteCond %{HTTP_USER_AGENT} ^Wget [NC,OR] RewriteRule .* - [F]