Hashtags and Trade Mark Law
: a Comparative and Doctrinal Study of Germany and the United States of America

Student thesis: Doctoral ThesisDoctor of Philosophy


Hashtags have become a highly visible part of online culture, and their application spans from simple, everyday conversational tweets to important political commentary and mobilisers of social change (e.g., #blacklivesmatter or #metoo). Over the last few years, businesses have increasingly started to use trade marks as hashtags and to protect hashtag trade marks themselves. This thesis examines the social media phenomenon of hashtags, and addresses the need to calibrate the legal protection of these versatile and powerful communicative and organisational tools. This comparative study evaluates whether existing approaches in major common law (primarily US) and civil law (primarily Germany/EU) trade mark and unfair competition regimes strike an appropriate balance between protection of hashtags and other important values such as freedom of expression, free competition, and questions of Internet regulation/deregulation.

As the first international and comparative legal analysis of the issue, this research also provides an original contribution to existing scholarship by placing hashtags within a broader context of the historical development of social media practices and linguistics. In doing so, it creates a new taxonomy of hashtags, which emphasises engaging in a deeper inquiry of their function rather than a superficial awareness of their commercial value and role in social movements. Understanding the communicative, expressive, and organisational — and often overlapping — functions of hashtags allows for a clearer perspective on how to balance their protection against other competing values.

Unfortunately, hashtags have been largely mischaracterised by courts and trade mark registries alike; contradictory outcomes illustrate their struggle to comprehend and keep up with technology-enhanced communications in both commercial and social contexts. Furthermore, the functionality issues of hashtags are often completely ignored, despite the potentially profound anti-competitive effects of this oversight. An un-nuanced approach to the protection and propertisation of such important digital tools could have negative social and economic effects. When registration is allowed to include different varieties of non-traditional marks — which do not primarily indicate source — and a showing of secondary meaning is not generally required, as it is in the case of hashtags, focus ought to shift to infringement and fair use as ‘controllers’ in order to maintain balance within the protection regime. As recent US jurisprudence indicates that expressive, referential hashtag use is not nominative fair use, a re-thinking of policies is necessary. Raising the bar on acquisition of hashtag mark protection and establishing strong fair use defences protecting other’s access to them, are solutions worth considering because most reproductions of most hashtags online do not create realistic risks of confusing consumers. Overprotection of hashtags would burden the legal system and economic efficiency, ultimately harming both consumers and market participants and depleting the public domain without any persuasive justification.
Date of Award1 Sept 2022
Original languageEnglish
Awarding Institution
  • King's College London
SupervisorBarbara Lauriat (Supervisor) & Tanya Aplin (Supervisor)

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