Don't use what?

Some of the trains in the Paris Metro have the following warning near the doors:
En cas d'affluence, ne pas utiliser les strapontins.

I know what it really means because I can read French, and some of them have English translations nearby, and my English is fine, but I like to think that it means: If you are rich, don't use strap-ons.
I think my translation is funnier.

(For those of you who are wondering, the real translation is: If the train is crowded, don't use the folding seats)