“I was taught that a father or grandfather can marry a girl off to whoever he wants, without asking her.”

The claim is stated with confidence, and it is false. A marriage contracted without the woman's consent is invalid, and the earliest sources say so directly.

The Prophet annulled such a marriage. A woman came to him and reported that her father had given her in marriage against her wishes, and he declared the marriage void. That report sits in the most rigorously screened collection Muslims possess, al-Bukhari, at hadith 7:69. Abu Dawud and Ibn Majah record a parallel case in which a girl who had not married before was given the choice to uphold the marriage or dissolve it.

The Prophet also set the standard plainly: a previously married woman is not to be given in marriage until she is consulted, and a woman who has not married before is not to be given in marriage without her permission.

What a person may have witnessed in a family, or in a community, or in a legal system that carries a state's name, is a separate question from what the sources require. Coercion happens. It happens against the text rather than because of it.

If the objection is that scholars have argued over the mechanics of guardianship, that is true, and it is worth reading them. The disagreement concerns who signs and who advises. It does not concern whether a woman may be handed over silently, because on that the ruling is settled.

Whoever taught this, taught it wrongly. That is worth being angry about. It is a poor reason to conclude that the religion itself sanctions what it explicitly voids.