Hi quellycatface, Although picketing an assembly will probably just feed the persecution complex of JWs' cult personas, I wonder if there are ways to present information to JWs that will not make JWs summarily dismiss it.
You probably would be better off attending the assembly and placing business cards with your favorite websites like www.jwfacts.com, www.freedomofmind.com, etc with QR codes in bathrooms or in WTBTS propaganda.
If you have JW family attending an assembly, I guess carrying a banner with "Hi Mum and Dad, Enjoying life free from the Watchtower" would not feed JWs' cult personas' persecution fears.
If you are willing to spend ~$200, you could set-up a literature cart with books by Steve Hassan, Raymond Franz, Don Cameron, and other cult experts and give away flyers/business cards where to buy books and/or e-books. I doubt many JWs would take any flyers, but displaying a large selection of books and giving away flyers with website names like www.jwfacts.com, www.freedomofmind.com, etc. may peak JWs' curiousity.
Peace be with you and everyone, who you love,
Robert