Something a little different for you guys this time. :)
Narcissists, sociopaths, and energy vampires in general are very toxic to us: they always try to latch onto us energetically, often by eliciting an emotional reaction. They are basically cut off from the Source and have to survive by feeding on the energy of other people. Spiritually-minded folks, "lightworkers", and empaths are often the primary targets: we have a lot of that good energy and tend to be more compassionate and easier to get a reaction out of. Empaths are often magnets for narcissists and all sorts of energy vampires.
I am still learning how to effectively repel these suckers, and these are just some techniques that have been working for me so far. Even though I put this in a humorous way, I'm not trying to make light of this (sometimes very serious!) situation, especially having lived through childhood with two vampire parents.
If you know of some other good methods, please share in the comments so we can all learn and become better at protecting ourselves!