[Windflier]

...if they can establish that his tenancy was predicated on his accepting their terms, including a prohibition on pornography. HE was the one in violation, since he had tacitly (or explicitly) agreed that the parents would not accept porn in their house.

That's a big IF, and even if the court finds for the landlords on that point, there's still the destruction of the tenant's personal property to be adjudged.

Bringing his porn collection onto the landlord's property could be judged as sufficient grounds for eviction, but that doesn't give the landlord the right to destroy the tenant's personal property.

[MrEdd]

I don’t see that at all.
The guy never retrieved some of his stuff for some time after leaving and then moved further away with the porn among the unretrieved items.

That’s abandonment, the same as if it were a storage unit.

You get nothing.
Good day Sir.