it wouldn't be an ai but if someone was paying for it i'd write a perl script with modules in perl using do and sub refs to load them into a hash, each module could be a new way to troll, for example one module to create a thread about writing an 'ai' to troll /prog/ and how to handle replies to that thread, all in the same module
for example you could have a list of known complaints and then reply with troll stuff like "i wrote a compiler when i was 12 years old BLA BLA BLA"