Freedoms of Expression

We focus on four of the freedoms guaranteed in the 1st Amendment: Press, Petition, Assembly, and Speech. How are we to understand these freedoms both as citizens, and naval officers? What limitations exist to those guaranteed rights? Why is okay for ordinary citizens to burn a flag or wear black armbands protesting war in public school? When does the government have the right to infringe upon some of those rights? Do they ever? And how are we supposed to understand freedom of expression in the digital age of Instagram and Facebook?