The social media buttons on this website are powered by Shariff, a privacy-friendly social media implementation by the german publisher Heise.
Normal social media buttons allow the respective social networks to track what websites you visit, even if you don’t click the share button. The shariff buttons do not load anything from the respective social networks until you actually click the button. That way, you control what they know about you, not me.
The Flattr buttons are also loaded from my server. They are using the “auto submit URL” feature of flattr to avoid having to load contents from their servers. The effect is the same as with Shariff: Flattr only knows you visited this website when you click the button. The downside is that you want to flattr me (thanks!), you have to confirm your click in the new tab that will open.