When executed, the backwards thrust can be both amusing and disturbing, while not offending the delicate sensitivities of some people.
Repeted backwards thrusting over time or backwards thrusting multiple times consecutively can result in several problems that include, but are not limited to:
-Thrusting into someone, creating an akward situation
-Attracting gays towards, or rather, behind yourself
<Bumps into front of other man>
<Other man smiles> "Helloooo."