Just to clarify, "Catfishing" - is merely contacting someone under a false identity in order to obtain something from them.
Its a form of on line fraud, usually based under the pretenses of starting a relationship or romantic interest.
Its has been used for many different criminal purposes, such as to obtain money, to defame individuals, to blackmail others, or to obtain sexual favors, and has in a few cases, resulted in murder.
Per wiki
"Catfishing is a deceptive activity where a person creates a fictional persona or fake identity on a social networking service, usually targeting a specific victim. The practice may be used for financial gain, to compromise a victim in some way, as a way to intentionally upset a victim, or for wish fulfillment."
There are plenty of stories , of people that have been defrauded out of thousands of dollars by people they have never actually met, people raped under the pretense of meeting someone for innocuous reasons, and people have even been lured to their deaths by people they never even met .
So an actual physical relationship does NOT need be established in order for one to be catfished .
As a matter of fact the entire premise of catfishing is based, on anonymity