What is a Sock Puppet
It's not literally one of these, cute as he may be. In context of this community, this is a Sock Puppet:
a false online identity, typically created by a person or group in
order to promote their own opinions or views. "both sides in the
debate use sock puppets to make it seem as if scores of people are
arguing a point"
There is lots of information on the term available on various Stack Exchange sites. More than it makes sense to list here. I will highlight this one:
It's important to realise here, that it typically is done by accounts controlled by one person but it doesn't have to be.
You can't ever be 100% sure. What you think is a sockpuppet could in fact be my good friend Nog Shine, who loves everything I write, copies my writing style, and uses my computer to vote and post stuff when I step away for coffee.
Enthusiastic co-workers can also be considered Sock Puppets. While we wouldn't (and couldn't) chase down every supportive co-worker who occasionally favours votes of one person over another, there is a discretionary line that absolutely can be broken - and should not.
Consider the example of John, upvoting co-worker Mary's first accepted answer on SSE to Peter, having just posted a question on SSE and now sends a mail around to his entire department asking them to log in and upvote it. (none of the names reflect any actual users on the site, they are picked entirely out of thin air :P)
So here's the thing:
Votes should follow the merits of the post, not the person or the technology
Anything going beyond this is, to some extent, Sock Puppeting. Upvoting all questions and answers for your favourite technology, is Sock Puppeting. Upvoting everything from your favourite person in the whole world, is Sock Puppeting.
In rare cases, a Sock Puppeteering involves a larger number of accounts. Internally in the mod group we call this for Karma Cartels. Or Voting Rings. Regardless of term used, the end result will be
the same. All votes cast internally in such a Karma Cartel can and will be invalidated at some point - account deletions and suspensions could also follow.
Another example could be certain third party technology or module related to Sitecore, featured in a Stack Exchange post. We've observed on some occasions, these are getting an unusual higher-than-normal amount of votes. Be mindful of this as well. And try to avoid questions that "pit" one technology against another - as these questions almost invariably lead to voting wars without any real value.
Why do we care?
It's about two things:
SEO value of our site. Stack Exchange sites are by default ranked very highly on Google and other search engines. This is - in part - because Google can "see" what content is
considered good for this community and therefore knows to highlight it. Sock Puppet voting breaks this - by giving merits to posts that are not necessarily broadly accepted in the community.
Fairness. A lot of you (us) enjoy the competitive aspect of the reputation system. If you use Sock Puppets to rise through the ranks of that system, it's entirely unfair to everyone else involved.