No, residential proxies themselves are not illegal; they use real user IPs with consent from ISPs or opt-in networks. However, a Backconnect Proxy using residential IPs can become problematic if used for illegal activities like fraud or hacking. Legitimate uses include market research, ad verification, and SEO monitoring, making this Backconnect Proxy type perfectly legal when applied ethically and within terms of service. Also read :- https://webavior.com/backconnect-proxy-service/