I have a standard moving box like this:
Of course, since I'm asking about it, they don't have a top-down photo. These are other photos, if they help you understand how it's constructed better: Flyttlådor 58 x 33 x 42 cm, 5-pack
Basically, the top folds kind of "lock together", but it's only for being able to stack them on top of each other; it's not actually locked, and anyone can trivially open it up from this "locked" state. It's just stiff paper with no string or padlock or anything like that.
If I use tape to seal the boxes, then I've just destroyed the boxes just for the sake of being able to move them once and knowing whether they have been opened or not (unless they also taped it after snooping inside...), and prevented their use as storage boxes in the new home. I obviously want to avoid this.
Same thing goes for that special "security tape" that you can buy which purposely leaves a pattern when removed, as to make it very obvious if it has been opened. That would also make the boxes "destroyed" in my mind. And none of these tape ideas actually prevent them from being opened.
I'm pretty shocked by how there seems to be zero information on this issue. I feel a huge amount of anxiety and stress around the very idea of having a bunch of scary and unreliable strangers handling my stuff whatsoever, risking that it gets damaged due to careless handling, but I'm even more scared that they will snoop inside and help themselves to my items, or that thieves will do that when we are inside the house and carrying the boxes from the house to the moving truck. Hiring somebody to stand guard there seems unrealistic.
Is there really no kind of standard product/mechanism that can be used to secure the top of the moving box so that it cannot be opened? Some kind of purpose-made strap which doesn't attach to the box itself, but keeps it tight and locked unless a knife is used to cut it or something like that?