None . Most free proxy operators log your IP address and browsing activity to sell to third parties or for malicious use. Common Dangers of Free Proxy Lists

: For scraping tasks, a proxy might return a "valid" response that is actually a block page or garbage data, contaminating your dataset without triggering an error. Safer Alternatives

: Some proxies inject malicious advertisements (malvertising) or code into the websites you visit to infect your device.

: Malicious operators can "pilfer" session cookies to hijack your accounts and impersonate you online.