In the incident subject to decisions made by 7th and 9th Civil Departments of Supreme Court in 2015, the union carrying out organization activities in the workplace, which is one of the most well-known dairy product companies of Turkey, has started a consumer boycott to stop purchasing products of the company, on the basis that unionized employees being dismissed from the company, until the employees dismissed due to union related reasons are hired back. After the employer terminates the employment contract of employees with just cause, who have supported the union boycott by liking/sharing union boycott on their Facebook accounts, on the basis of violation of duty of loyalty, aforementioned employees filed a re-employment lawsuit against the company claiming that their employment contracts have been terminated for union related reasons, and sued for a re-employment verdict. Decisions of Departments were poles apart; 9th Civil Department has focused on the boycott for no purchase call and reached the decision that employees supporting the boycott have violated their duty of loyalty, while 7th Civil Department focused on the purpose of the boycott, reaching the decision that boycott was a democratic activity and employees support for the boycott was a union activity. In our study, the concept of boycott, effects of expressions made on social media on employment contracts, employees freedom of expression, and relations between freedom of expression and duty of loyalty will be assessed, investigating aforementioned decisions in line with these headings.