Personal sites using Web 2.0 but a older issue - New starters... What do you think?

Headteachers use the internet to check up on staff, say union officials
Teachers who post photos of "inappropriate behaviour" social networking sites could face disciplinary action

This is an issue that a number of professionals on the course have mentioned - but here it is again about personal sites... The question is, can professional sites have an opposite effect? Comments please...