[Plugin: Facebook Like Button] This is spyware

Just to reiterate what was said in the post I’ve linked to below and make sure that this issue is more visible, when you activate the plugin it sends your email address to the plugin author along with your site name and url.

It also contains a function that can be used to ping your site to check that the plugin is still installed and active.

http://wordpress.org/support/topic/plugin-facebook-like-button-meh?replies=2