that would be the easiest bust that cop makes.
don't do it, ignore him, and keep going with your life...
that was a cop going through the forum reading, carefully, looking at pics, analyzing posts, then he noticed you screwed up by letting them know your general location. he then set up a bullshit account and put up sum posts just to look "legit" and asked you for that "favor".
while you are here considering it he is calling the cavalry to set up a sting operation should you choose to be stupid.
the cops know everyone here is growing, it's just impossible to prove where those pics we put up were taken. they might know where you live, they know you have seen marijuana plants, they might even know you are actively seeking to harvest and smoke all that bud....but they can't prove anything without the plants, without a rat, or you being a dumbass...... they cannot prove you are growing, hell it's pretty hard to find probable cause. and no proof or probable cause = no warrant, which means no search and no arrest.
that's why they need for things like this to happen, for them to entrap people, for them to scare rats into snitching, they have no proof, and they know it's staying that way unless they engage in shady police work.....
remember this too:
http://www.youtube.com/watch?v=6wXkI4t7nuc