From (almost) open to heavily restricted data access – The development of the Twitter/X developer policies

Archiving data is a crucial practice, as it ensures reproducibility of research and aligns with the FAIR principles (Findable, Accessible, Interoperable, and Reusable). To facilitate data sharing, it is essential to understand the legal conditions, especially in the form of policies, at the time of data collection. However, these policies can be difficult to locate, change over time, and may even disappear as new policies are introduced. Terms of Service are a common form of such policies. With the growing use of Twitter/X data in the social sciences, and the restriction of access to the data by the platform itself, investigating ways of sharing of this data has become even more important, and having Terms of Service at hand to check the legal conditions at the time of data collection is a crucial task. To illustrate this use case, we compiled a complete collection of Twitter/X's conditions for sharing data from 2006 until 2023. Using both qualitative and quantitative approaches, we analyse how data sharing conditions have changed. We find that while the Terms of Service become increasingly longer and more complicated, their restrictiveness varies over time. However, our analysis further shows that sharing of full tweet objects both in retrospect and in the future is not usually covered and thus affecting the reproducibility of research as rehydration of tweets is no longer feasible.