As I pointed out these "vendors" are breaking laws in several countries. As far as a freedom of speach issue goes you are correct, nobody can fault you for linking to another on the web... but by highlighting these vendors so prominantly on YOUR site might likely be construed as "endorsement". That could get you in a pile of hot water given several are criminal enterprises. (I'm talking about the seed dealers and the weed deliverer, not RiverRock).
RiverRock is an illegal business in the United States, same as all other Colorado marijuana businesses which lack permission from federal authorities. Tomorrow morning, the US drug enforcement agency can go to Colorado and Washington and start making arrests and seizures. Only thing stopping them is in the current man in the white house. Banks won't openly accept marijuana businesses because they know such businesses are currently illegal.
Actually your interpretation is all wrong. RiverRock and 500 other dispensaries in Colorado are exercising their right to civil disobedience. Further, the Govenor of the state CONDONES this activity. Further, the Department of Justice has SPECIFICALLY stated through a letter penned by David Cole that they will not interfere in our state regulated industry. Further, the Republican led house recently voted to de-fund the DEA in all states where medical marijuana is legal. Further, banks DO accept the accounts (per news releases linked to in this thread), there are several companies implementing token based systems using ATM machines and there is an effort within Colorado to provide co-op's as banks.
The seed dealers and weed mailers, on the other hand, are following no known law nor are they working within any type of government program or any type of regulating system. These people, the outsiders, are what we insiders CONTINUE to call drug dealers. In Colorado we follow laws and regulations.... this isn't some game. RiverRock is NOT a criminal entity.