Invalid traffic & fraud
Residential proxy
A residential proxy routes internet traffic through real home or mobile IP addresses, making automated or fraudulent traffic look as if it comes from ordinary households instead of servers.
Most bot traffic starts on servers, and server IPs are easy to recognise and block (see data center traffic). Residential proxies hide that origin by relaying the traffic through IP addresses that belong to consumer broadband and mobile connections. To a website or ad platform, the visit appears to come from a normal home.
Proxy networks obtain those IPs in different ways. Some pay users or app developers to share bandwidth, often via SDKs bundled in free apps, with consent that users may not understand. Others rely on malware and botnets. The US Department of Justice said in 2024 that the 911 S5 network it dismantled had used millions of infected Windows computers this way.
Residential proxies are not illegal in themselves and have legitimate uses, but for ad measurement they are a major problem, and the MRC IVT guidelines list invalid proxy traffic as SIVT. Detection combines IP reputation feeds that track known proxy exit nodes, mismatches between IP location, time zone and device language, network latency patterns, and device fingerprinting inconsistencies. IP checks alone are no longer enough.
Think of it like this
A residential proxy is like a burglar borrowing a neighbour's front door to come and go, so the CCTV shows only a familiar house.
An example
A bot operator's traffic, blocked when it came from a cloud host, reappears through 200,000 different home IPs across the US and Canada, but every session has the same browser build and a system clock set to Eastern European time.
Related terms
Data center traffic
Data center traffic is ad or web activity coming from IP addresses owned by cloud and hosting providers rather than homes or mobile networks, which usually means automation rather than a person.
Botnet
A botnet is a network of computers, phones or smart devices infected with malware and remotely controlled by criminals, often used to generate fake ad impressions and clicks from real consumer devices.
IP address (in advertising)
In advertising, an IP address is the network address a device uses online, used for rough geolocation, household matching, frequency capping and fraud detection, and treated as personal data in many laws.
Bot traffic
Bot traffic is visits, ad impressions or clicks generated by automated software rather than people, ranging from honest search crawlers to fraudulent bots built to look human.
SIVT (sophisticated invalid traffic)
SIVT (sophisticated invalid traffic) is invalid traffic designed to look human or legitimate, which can only be found through advanced analytics, multi-point corroboration and often human review.
Sources: MRC Invalid Traffic Detection and Filtration Guidelines Addendum (2020 update)