<a href="https://www.facebook.com/.../share" target="_blank">
<img src="share_button.png">
</a>
? <a href="https://www.facebook.com/.../share" target="_blank">
<img src="share_button.png">
</a>
?Edit: You could probably hack around this with some CSS, but only relatively recently and browser support could be a challenge.
(In this specific case, it will most likely only ruin analytics. However, it's a good habit to use POST when you don't want automated access. E.g. if the social media also didn't implement their end properly and used GET requests for submission, the bot or crawler or whatever will fall through two layers of checks and your social media may be filled with gibberish, this scenario is however mostly theoretical. In general, you don't want a URL can modify state related to your core business logic. See HN's infamous "This Submission Upvotes Itself")
I was discussing this in another HN thread recently and my mind hadn't switched out yet :)
All the major platforms allow you to pass through titles and other data to pre-populate the share box.