Not TB specific but a general etiquette on social networking we all can use from time to time, especially if we are open about our identities.
It's also a good idea to read your employers "Social Media" policy.

Whether or not there is bad blood between you and your previous employer, badmouthing an ex-employer in public is career suicide nothing is more public or more enduring that words printed into the Internet on social networking sites.
How to Resist the Urge to Badmouth an Ex Employer on Social Networking Sites