>One is that they ofter change IP addresses during a single web session. Second, if IP come from the same proxies provider, they are often concentrated within a

>One is that they ofter change IP addresses during a single web session. Second, if IP come from the same proxies provider, they are often concentrated within a sing ASN, making them easier to detect. Both are pretty easy to mitigate with a geoip database and some smart routing. One "residential proxy" vendor even has session tokens so your source IP doesn't randomly jump between each request.