I was using SexyBookmarks for like a year or two
and with the latest version they started to inject first:
an google analytics file to track my site (unwanted by me)
then after a guy reported (http://wordpress.org/support/topic/plugin-sexybookmarks-warning-v-326-adds-google-analytic-code) that they can be sued they put an option where you can switch if you want or not this file to be loaded.
but in the latest updates they also put another file hosted on cloudfront
this file takes all the information about the users visiting your site and sends them to different ADVERTISING and TRACKING WEBSITEs;
-- w55c.net --> http://www.donottrackplus.com/trackers/w55c.net.php
making money with our users without asking our permission, this means that every time a user visits your site a lot of "personal" data is sent to third party services and will be used for commercial use, later.
THERE'S NO FILE OR ANY LINE SOMEWHERE THAT WARNS YOU ABOUT THIS... OF COURSE they are making money with this...
SO BEAWARE FOLKS they have nice graphics but also tracking your visitors and selling crucial information to third party
[BTW I DONATED TO YOUR PLUGIN, AND THAT'S WHAT I GOT?]