http://www.tmx.com/en/listings/newsletters/article_2.html

Paragraph 3 reads:

C-level executives need to realize that the discussion about their company is likely happening online with or without them. At the very least, by using social media public companies are more likely to discover how investors and other business stakeholders truly perceive them. A public issuer's best chance to have some degree of control over the messaging, and the perception of their company, is to join the discussion.