Because help is at hand from various sources.
Firstly, there’s an excellent article from Inc.com about social media guidelines for employees (and why it’s important to have one or several – one each for each different social network, as each network carries with it unique risks and opportunities).
Secondly, there is an online database of hundreds of examples of social media policies that you can wonder through for inspiration when creating your own.
Thirdly, there’s a template toolkit you can purchase (US$149) that allows you to pick and choose your ideal policy/policies.
And as a further thought, remember to get your lawyers involved too; it will help with crossing the ‘t’s and dotting the ‘i’s.