I'm working on a site that still includes the meta keywords tag on a lot of pages. No one is actively spending time optimizing these (they are a legacy thing). I know this tag is ignored by most search engines, but I've heard speculations that just the presence of the tag on a site may actually be a negative factor. Does anyone have opinions or even concrete evidence whether or not meta keywords is a negative ranking factor? The tags on the site I'm looking at are not particularly spammy. It is a US based site doing business in the US.