Article 19 provides 'reasonable restrictions' on the freedoms granted by it, which means that these rights are conditional. The State can 'reasonably' limit or take away the right to 'freedom of speech and expression' when there is a threat to the sovereignty and integrity of India, or the security of the State, or friendly relations with foreign States, or public order, or decency or morality, or in relation to contempt of court, or defamation or incitement to an offence. For example, the State can prohibit someone from making inciting speeches that may provoke others to commit violence. 

However, at times Supreme Court can invalidate State's restrictions if it finds them to be unreasonable. As an instance, State cannot put restriction as an excuse because it is unable to maintain public order, e.g., application of aforementioned restrictions on the sale of a book because of a few unruly protesters; such restrictions are unreasonable and breach the right to freedom of speech and expression of the author.