On Slashdot, a high-traffic technology news website, there is a moderation system based on score. Traffic alone guarantees the difficulty of obtaining the first post, which is rewarding for the user. Such comments are generally frowned upon and attributed a negative score by the moderators.
Frosty Piss is therefore intended to be a near-anagram of First Post. Many other anagrammatic variations exist, depending only on the user's boredom and creativity.
Subject: FROSTY PISS!!!!!
Body: OMG I GOT THE FIRST POST! WHEEEE!