tac channels

I have a few questions about the laws regarding police/law enforcement TAC channels. What can & can't you post regarding the information you're hearing on the TAC channel(s)? If there's a restriction on what can be posted in real-time, is there a certain amount of time after such as 30 mins or...

I've never heard activity on these frequencies the ones with 167.9 pl, should I just remove them from my scanner? Has anyone heard activity on these channels?

fire dept is use a new tac ch now it is 155.620 pl 107.2