At some point, you may run your site through the W3C validator. All Shareaholic meta tags are officially registered with W3.org and should not return any warnings. The information contained in these meta tags is used by the Shareaholic Content Amplification System to learn more about your content and website.
In-case a non-W3C 3rd party validator does return a warning, don't worry. This is not a cause for concern as these meta tags will not interfere with the functionality, SEO and/or rendering of your webpages.
For more information: