Would you yourself consider lifetime seclusion? Why, you cause harm to billions of living creatures every time you venture outside. (Although sitting in solitary jail cell only reduces that by a negligible factor). And that's only taking into account direct harm, third or fourth-order consequences of being out there are impossible to even start comprehending.

If not, why you think it's okay to condemn another living creature to such a life sentence? After all, its well-being is just as important as yours, is it not so?