To attempt something which, in the face of a massive adversary is equivalent to trying to drown out a thunderstorm with a feeble fart. Can also be used as an exaggerated way of describing how one's attempts at 'getting the message across' to an individual or party were met with a overpowering sense of hopelessness and futility. Often out of pure frustratrion.
Trying to speak to the manager about my complaint was useless. All she did was talk-talk and not listen. I might as well have been farting against thunder!