Time spent in prison is unlikely to be joyful for the inmate.
The law applied to those who were found excavating in their dwellings and were prosecuted as a result. In addition, they were charged with animal cruelty. Courts were under pressure from the public to punish them in proportion to the seriousness of their offences, and they did so.
As a result, the culprits all received hefty prison sentences in order to dissuade others from committing crimes of this nature in the future. Criminals received the punishment they deserved, and the public is now aware of the seriousness of animal abuse.