Why Is This Website Port Scanning Me? (nullsweep.com)

Article summary

The article discusses how some websites, including eBay, are performing localhost port scans on visitors, potentially as part of user fingerprinting and tracking or bot detection. This technique allows websites to gather information about the software and services running on a user's computer. The author argues that this practice is malicious and may be illegal. The article also explains how port scanning with WebSockets works and how it can be used to determine if a certain port is open.

Main themes

• port scanning
• user fingerprinting
• bot detection
• CFAA legality
• web security
• privacy concerns
• malicious practices

What commenters say

• Port scanning without consent may be a violation of the CFAA, but its legality depends on intent and context.
• Some argue that port scanning is not illegal, citing the existence of services like Shodan that perform similar scans.
• The use of port scanning for bot detection and user fingerprinting is seen as a potential reason for eBay's behavior.
• Others believe that port scanning is a malicious practice that can compromise user security and should be blocked by browser extensions or mitigated by browser vendors.
• The CFAA is considered by some to be too broad and in need of repeal, as it can be used to prosecute individuals for activities that are not malicious.
• Some commenters think that eBay's port scanning is likely part of a heuristic to detect bots, particularly those using VNC or RDP ports.
• The practice of port scanning is seen as a potential threat to user privacy and security, and its use by commercial companies is viewed with skepticism.
• The legality of port scanning is uncertain and may depend on the specific circumstances and motivations behind its use.