Calculating:

2.7 (txs/s) * 60 (per minute) * 60 (hour) * 24 (day) * 0.0001 (fee) * 20 (Gavin factor) * 200 (usd price) = 93312 USD to spam up Gavincoin to full 20MB blocks and render it unuseable aswell as filling up peoples' harddrives around the world with 2,88 GB of data per 24 hours (!!!)

conclusion:
Gavincoin can not be defended against banks or governments or even a (bitcoin)millionaire

Anyone who is willing to spend around 100k$ per day can make Bitcoin unusable for almost anyone and bloat the chain in an extreme way and doesn't even need any mining equipement for the attack!

A measily 40 Million spent on such an attack would bloat the chain to 1 Terrabyte. For many entities that's not a lot of money.

#justsayin'

Gavincoin is not defensible against spam.