ANSWER: When the Confederate soldiers come through town, they remove all of the Union flags. Barbara Frietchie is upset that her flag was removed. She puts her flag back up in the attic window, risking her life to stand up for what she believes.
Found one: <span> The great black forest--stern as it showed itself to those who brought the guilt and troubles of the world into its bosom--became the playmate of the lonely infant, as well as it knew how.</span>
The main reasons are to protect your legal identity & privacy.
Another reason is to brand yourself like they do in the entertainment industry (some examples are: Oprah, Pink, Shakira, Madonna, Ice-T, etc.)