first of all it would not be the feds that are after you, it would be the DEA. second of all that is not how the DEA finds their leads they usually get a tip from someone who has turned informant for one reason or another (to get paid, to get a lighter sentence etc.). so be selective of the company you keep. once they get a tip they start to watch you in order to compile evidence, build a case against you, and eventually present their case to a judge in order to get a search warrant. so if you are posting tons of picks of your grow it will not exactly lead to a bust but it wont help you either if you are under investigation. do not talk on the phone about anything illegal or in text messages (these can be kept forever by you service provider). if you think you have been ratted on (has anyone you know been busted recently?) be very careful.