If you think someone dodgy, then don't communicate with them, or at least no personal details.
Everyone on here has probably got a healthy para, but personally I think that if the cops are tracing people through this site (or any others), then they really are scraping the bottom. Most people I talk to on here are only doing it for personal, and always say so. 1st time bust for a couple of plants - you'd only get a slap on the wrists. Not really worth it for them. Still though - you have to be careful.