Animal liberation as an active act of compassion is debatable.
Like any other acts of compassion, it must come with wisdom and skilful actions.
In ancient times, we get our food from the nature environment in the wild and forest. Nowadays, our food sources are never from the wild or captured from the forest but from commercial farms and most of the released animals are farmed animals. Farmed animals do not know how to look for their own food or hunt in the wild.
Releasing farmed animal in any manner to the nature does not ensure survivability of the animal and is committing murder of the animal because of our intervention. What difference does it makes if animal are killed by the butcher or eager Buddhists who release them and let them die on their own.
Animal liberation is a futile and ineffective way of caring for life in this new world. Buddhists who hope to collect Merits out of this exercise is extremely ignorant and is only feeding the animal traders and encouraging them to import more for the new group of Buddhists customers. Just ask any traders and even Sheng Siong managers are aware of this group of new customers and stock in more to meet their demand.
The field of Deep ecology encourage human to stop manipulating nature for their ego and greed. Buddhists should always use their wisdom in such exercise.
Active compassion for animals can be channelled to support food for stray animal, stop buying animals for fun and wear its skin or other products, stop fishing as a hobby and care for all animals that we come to contact with.
Such Buddhists' action on animal liberation is certainly one with good intention but no skillful methods.