Final answer:
Discipline cases related to whether a message on social media violates employer policy or interests typically involve social media. Landmark cases have set precedents for allowable restrictions on speech, and these apply to the workplace as well, including in social media contexts.
Step-by-step explanation:
Discipline cases where arbitrators focus on whether the substance of the message violates an employer policy or infringes on some legitimate employer interest most commonly involve social media.
Given the widespread use of social media platforms, they have become a battleground for determining what constitutes protected speech in relation to an employer's interest.
As seen in landmark cases such as Tinker v. Des Moines (1969) and Hazelwood v. Kuhlmeier (1988), speech that substantially interferes with school discipline or infringes on the rights of others is subject to restrictions. This principle extends to employment settings, where expressions made on social media can be scrutinized under employer policies and could lead to disciplinary actions if found in violation.
Moreover, legislation has evolved to address concerns such as workplace harassment, discrimination, and safety issues, all of which can be implicated by inappropriate social media use.