I noticed this last night and it keeps bugging me. The rack outside is only held down with a single finger tight bolt. If you lock it well to the smaller triangles, it will be a little safer, but the thicker post would roll right out of any lock.
I’m still in “not yet a member” status, but best results would be 2 nuts and a lock washer per side - as tight as possible.
Best would actually be welded, but I’m not sure that’s how the property owners would approach it. Certainly it gives more reason for opportunists to linger so I would think they’d be on-board with it.