You have to assume the LEOs are watching everything connected to growing. They monitor grow stores. They've data mined online retailers as well. They monitor power records. They do flyovers looking for heat signatures. What's Ironic is that sometimes, they aren't even following the laws that they're supposed to be enforcing. Illegal searches, excessive force and intimidation are common tactics used to secure confessions. After someone confesses, they don't think they need a lawyer, so they never get their case thrown out and the cop gets a gold star on his record.
You have to assume that LEOs are monitoring everything posted on this site. To get IP information to track you down would require a warrant and a formal request for data from RIU. If you're admitting to doing something illegal, you'd better be at least using Tor which is a free random peer proxy network. This makes it considerably more difficult to pinpoint the origin of the posts. (Learn more at
http://www.torproject.org) I'd assume that they have better things to do then go after every home grower in the country. You could probably post pictures of a plant or two without using a proxy service and most likely you'll be fine. If you post a picture of what will amount to 10 lbs of dried buds, you have to reasonably expect some form of investigation.
Either way, it's best to err on the side of caution and just don't do anything that would catch the eye of a LEO as a potentially huge bust.