So-called conversion therapy is never acceptable. It assumes that being gay is a mental illness, which is no longer accepted as medical fact; it assumes that it is possible, and

medically indicated, to alter a person’s sexuality by unproven and potentially dangerous methods. Conversion therapy ( which is not therapy at all) is particularly damaging and dangerous if it is practiced on young people whose ego-strength is not fully-developed. 

Conversion therapy should not be legal. It is both ineffective and harmful.