Even so, it is not prudent to just turn off the entire water hose. Ok, you don't want your employees using social media sites during work time, but that doesn't mean you don't want some other company's employees connecting with your business during their work time!
Possibly the biggest reason company executives reject social media is because the term is vague in detail and, leading on, because it is unclear just how social media, whatever that is, actually contributes to the bottom line and closes the gap towards the business objectives.
Part of the reason social media is unclear is because it encompasses just such a wide variety of sites and services. WordPress, Facebook, Twitter, even YouTube are all considered a part of social networking - as are wikis, communities like Reddit, and bookmarking sites such as StumbleUpon.
The truth is social media comes in many forms and facets but at heart, social networking is about dialoging and communicating with people interested in your site, your goods and services, and doing so in a way which is more relaxed than a traditional sales call or marketing presentation.
Social networking can be of benefit to your business in many ways.