Talk is cheap, show us the code
Sure thing. These things are really old, people used them to spam newsgroups and stuff, so they're easy enough to find on the internet.
I made a really small corpus from a few posts from the last couple of pages from this thread and got this:
Wise, they will quickly get devalued and people cant spam anymore.
Suffice at least theyre not being too lazy well thats why members looking and striving for power should do something similar by changing a word
If the spammers to a moderators position too many bans for too little effort and severely damage the forum reputation as well
He is modifying your own posts above?
Here's the code I used, it was on the first page of Google

#!/usr/bin/env python2
import random
import re
FORBIDDEN = '[]()"\''
TRUNC = re.compile('([!?.]+).*')
class Markov:
def __init__(self, data=None, order=3):
self.chains = {}
self.order = order
if data:
self.add(data)
def add(self, data):
data = ' '.join(data.lower().split())
for x in FORBIDDEN:
data = data.replace(x, '')
for i in range(len(data)):
key = data[i:i+self.order-1]
val = data[i+self.order-1:i+self.order]
if key not in self.chains:
self.chains[key] = []
self.chains[key].append(val)
return self
def generate(self, max_length=140):
try:
current = random.choice(self.chains.keys())
length = 0
generated = []
while length < max_length:
last = current
current = random.choice(self.chains.get(last, ['']))
generated.append(current)
length += len(current)
if any([x in current for x in '!.?']) or not current:
break
current = (last + current)[1:]
return TRUNC.sub(
lambda m: m.group(1),
''.join(generated).strip().title().capitalize()
)
except:
return ''
if __name__ == '__main__':
import sys
print Markov(
unicode(sys.stdin.read(), 'utf-8'),
order=int(sys.argv[1])
).generate()