Pro-drug advocates have flooded FBI with over 200 messages of protest following the raid on Silk Road, an online marketplace for illicit goods.
The agency was trying to access 600,000 Bitcoins, worth around $80 million (£49.7 million), accumulated by Ross Ulbricht, the alleged mastermind behind Silk Road, but had 26,000 ($3.2 million) that the site had held in escrow for its customers.
The agency has transferred the Bitcoins to a new address on blockchain.info from where users could manage their Bitcoin accounts.
However, many Silk Road users were able to identify the FBI's wallet details and used blockchain for posting publicly viewable messages along with small transactions.
Though most were of the order of 0.00000001 BTC (0.0001p), users could vent their anger at the seizure of their virtual cash.
In one post a user said, ''Take the drugs, take the domain, but don't take the people's Bitcoins. This seizure was only legal because Bitcoin is not recognized as a currency?''
Another quoted Thomas Jefferson, one of the founding fathers of the US, and called for the end of the Federal Reserve: "The issuing power should be taken from the banks and restored to the people, to whom it properly belongs".
Meanwhile, according to Forbes, if the $80 million estimate of the FBI was correct, it would mean 5 per cent of all Bitcoins on the market were under the control of Ulbright.
Though FBI has still not been able to resolve the encryption difficulties, the bureau still controlled Ulbricht's Bitcoin wallet, meaning its contents were out of bounds to all and the $80 million would remain in limbo for as long as the agency could not crack the safe.
The report confirmed Ulbright's complete control over Silk Road, and its operations. According to the criminal complaint by the FBI, aside from a handful of administrators he had hired, Ulbricht managed the bulk of the site on its own, including its finances.
The Bitcoin account had been renamed ''Silkroad Seized Coins'' on Blockchain, the site that tracked all activity on the Bitcoin network.
The visibility would only add to the pain of Silk Road users, who had no chance of re-claiming the Bitcoin they had stored on the site, the FBI spokesperson told Forbes.