The preferred way to signal issues to send an e-mail (see Support Email on add-page page).

This problem comes from the fact that Twitter and Facebook use non standard HTML elements to input data. You can solve your problem by blacklisted the problematic page or site:
* For twitter, blacklist url "twitter\.com/compose/tweet"
* For Facebook, no other solution that blacklisted complete site. So blacklist "www\.facebook\.com"