Reddit mentions of All Purpose Clear Acrylic Box

I used to work in the exhibitions department at a prominent museum in New York and learned quite a few things about how aggressive people can be when it comes to "public displays".

My advice: Rethink your cache. If a person can touch the thing that you don't want them to take, they're going to take it. It doesn't matter what kind or how much glue you use. They'll break it off and take it with them. So, what to do? Change your cache box. I don't know how you've got it set up now so my logistics might be way off, but let's say you're using an ammo box. I would get ahold of a clear acrylic box with a lid, something like this, that fits inside of the ammo box. Open the box and affix your figurines to the bottom using a small dab of water-based glue. Let it dry, then fill the bottom half inch or so with clear casting resin. When it sets up the figures won't be going anywhere. You can then glue the box shut (use more casting resin to make a nice clear bead, set the box upside-down to dry) and put it in the bottom of your ammo box.

Alternately, you can do the same thing but rather than a box with a lid you can just fill the box with casting resin, effectively making a big paper weight out of the whole display.

The biggest problem with any of this, of course, is that someone could conceivably walk away with the whole display. You may be able to negate that by "permanently" attaching the display to your box. A couple of stainless steel security screws through the ammo box and into the plastic (drill pilot holes first) might help with that.

You could always make one out of acrylic.

I dont think this would really work, but it's about what you could expect to find. It's a great material to work with, it probably wouldn't be too difficult to make yourself out of sheets.