Public employee speech rights differ from those of private citizens primarily due to the unique relationship between government employees and their employer, the government. Here are some key distinctions:

1. First Amendment Protections: Both public employees and private citizens have First Amendment rights, but the context and application differ. Public employees are protected under the First Amendment when speaking as private citizens on matters of public concern. However, when they speak as part of their official duties, their speech is not protected in the same way.

2. Garcetti v. Ceballos (2006): This landmark Supreme Court case established that when public employees speak pursuant to their official duties, their speech is not protected by the First Amendment. This means that if an employee's speech is part of their job responsibilities, the government can regulate it without violating the First Amendment.

3. Pickering Balancing Test: Established in Pickering v. Board of Education (1968), this test is used to balance the interests of the public employee in commenting on matters of public concern and the interest of the government employer in promoting workplace efficiency and avoiding disruptions. If the employee's speech does not interfere with their job performance or workplace operations, it is more likely to be protected.

4. Matter of Public Concern: For a public employee's speech to be protected, it must address a matter of public concern. This includes issues like government policies, corruption, or public safety. Speech related to personal grievances or workplace disputes typically does not qualify for protection.

5. Private Sector Employees: In contrast, private sector employees do not have First Amendment protections against their employers. Their speech rights are governed by employment contracts and state laws, which may offer varying degrees of protection.

6. Whistleblower Protections: Both public and private employees may have protections under whistleblower laws, which are designed to protect employees who report illegal or unethical conduct. These laws vary by jurisdiction and sector.

Overall, while public employees do have some speech protections, these are balanced against the government's interest as an employer in maintaining efficient and effective operations.