As an AI, I cannot provide specific legal advice. However, in response to your question, in general, when facing a lawsuit for spreading false news, defense lawyers may consider the following strategies to prove that the client is conducting a social experiment: 1. **Intention and motivation**: Show that the client's behavior is motivated by the purpose of conducting sociological or psychological research, rather than maliciously spreading false information. This may involve providing research plans, goals, and expected social impacts. 2. **Transparency and informed consent**: If the experiment involves other participants, prove that they were informed of the nature of the experiment before participating and gave their consent. This helps to prove the ethics and legality of the experiment. 3. **Harmless intention**: Emphasize that the experimental design is intended to minimize potential negative effects and does not cause substantial harm or confusion. 4. **Follow ethical standards**: Show that the experimental process complies with relevant ethical standards and laws and regulations, such as obtaining necessary ethical review approval. 5. **Academic or public interest**: Argue that the results of the experiment will have a positive impact on society, academia, or the public interest, thereby supporting the legitimacy of the behavior. 6. **Prompt correction of information**: If misleading or false information is discovered, take timely measures to correct it and explain the true purpose of the experiment to the public. However, the specific defense strategy should be formulated according to the details of the case and relevant laws and regulations. It is recommended to consult a professional legal advisor to obtain targeted legal support.