The virtuality fallacy is a name given to the informal fallacy of combining two premises together to prove that something is not real. The fallacy has the following form:
Premise 1: X exists in the virtual world
Premise 2: Virtual is not real
Conclusion: X (or the effect of X) is not real
This fallacy is mostly used by those who want to defend their own questionable behavior on the internet by saying this is not real and will not cause any harm to other people.
References
Virtuality fallacy Wikipedia(Text) CC BY-SA