I would not recommend this plugin AT ALL until

the new developer removes the hidden built-in facebook app. By hiding the app in the code, it gives the developer all of your facebook share tracking data, rather than to you, the site owner.

In the code there’s a few lines that basically state the original developer can’t keep up with it anymore and a company called LinksAlpha is taking it over.

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“The last years I have been amazed at how well received this plugin has been. Sadly, I find myself unable to effectively combine further development and, more importantly, support with my other obligations. This is why I agreed to transfer further development and support to LinksAlpha. I fully expect that the current quality of the plugin will be maintained and improved under the care of LinksAlpha.
~ Marijn Rongen, Active-Bits – July 2013″

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I don’t know if it is the company or the original developer that has hard-coded their facebook application id into the plugin, but in a nutshell, while your content is getting shared, they are collecting all of the data about your users. Legitimate facebook social sharing plugins do not do this; they ask you for your fb app ID, they don’t force you to use theirs without providing any way to opt out of it.