Computes the hash of a favicon (the tab icon) the way Shodan does, then lists the Internet servers indexed with the same icon. A website hidden behind a CDN often shows the same favicon on its real server. Paste the address of a Lab favicon or choose a file.
or
In real life: Shodan (http.favicon.hash: filter), Censys, FOFA. The favicon is base64-encoded then hashed (MurmurHash3); engines that scan the whole Internet can thus find an origin server the CDN was meant to hide.