Big data has substantially improved the efficiency of information collection and processing (Fadhil et al., 2021). (Fadhil, S. A., Kadhim, L. E. and Abdurazaq, S. G. (2021) ‘Protection measurements of computer network information security for big data’, Journal of Discrete Mathematical Sciences and Cryptography, Vol. 24, No. 7, pages 1959–1965, doi: 10. 1080/09720529.2021.1959996). Nevertheless, the transparentizing and openization of information could also increase the risk of disclosure of personal information and business secrets, leading to various illegal and criminal activities (Lim et al., 2018). (Lim, S., Woo, J., Lee, J. and Huh, S. -Y. (2018) ‘Consumer valuation of personal information in the age of big data’, Journal of the Association for Information Science and Technology, Vol. 69, No. 1, pages 60–71, doi: 10.1002/asi.23915). This paper adopts qualitative analysis and single-case study to investigate the approaches and outcomes of network information collection. It is found that many e-commerce platforms utilize big data technologies to collect, screen and process customer information. Yet, the collected customer information might be maliciously used by others to infringe on personal privacy, result in property damage and loss, trigger unhealthy market competition, and hinder economic development (Taylor, 2017). ((Taylor, I. (2017) ‘Data collection, counterterrorism and the right to privacy’, Politics, Philosophy & Economics, Vol. 16, No. 3, pages 326–346, doi: 10.1177/ 1470594X17715249). Thus, this paper recommends that the application of big data should have a legal boundary. It needs to be strictly defined and regulated to facilitate its positive role in protecting cybersecurity and promoting fair market competition. Big data, business secret, cybersecurity, data right, e-commerce platform, information processing, legal boundary, market competition, network platform, personal privacy