Obviously they did. So why now is Greg freaking out about censorship and "theocratic authoritarianism"? Its ridiculous to suggest that filters for non-monetary transactions are a slippery slope towards censorship.

fourrules

bitcoin

Gmax's theocratic populist sex prohibition analogy for filters

Scoresby

it's not really novel, there are ways of dealing with a Sybil attack on nodes. basically web of trust. 

there's a primitive version of that already baked in with the bootstrapping, everybody trusts Bitcoin core basically 

if the Sybil attack gets really aggressive we may need to do better than that. 

but it's not like no one ever thought of this. they thought about it... a lot. 