The Ethereum network is experiencing copious transactions all connected to a single account, leading to broad speculation about their purpose.

A strange series of transactions on the Ethereum network began yesterday, leading to speculation that the network was the victim of a spam attack. The transactions are all connected to a single address, which is now involved with the bulk of Ethereum transactions.

Starting around 2:45 UTC Monday, the address in question received its very first transaction, a transfer of 0.02 Ether. In the next fifteen minutes, 600 transactions were made to that same address.

The transactions have continued at that pace, with the address racking up more than 48,000 transactions in the last 30 hours. Most of these transactions involved the transfer of 0.02 Ether and had a transaction fee of around 0.004 Ether. This means that if it is an attack, it has been a fairly expensive one for whoever is orchestrating it. The total transaction fees likely exceed 160 Ether by now (a value of somewhere in the neighborhood of $61,000 at time of press).

Several comments on Etherscan indicate some believe the transactions were a coordinated spam attack on the network. One user wrote:

“It’s a botted ring wallet system with nearly 150,000 to 200,000 [Ether] in it. The bots translate random addresses to other random addresses and random amounts of eth to make them difficult to spot on block history.”

One commenter even speculated rival blockchain EOS was coordinating an attack. EOS members are planning a stress test on the EOS system tomorrow, hoping to set a record for transactions-per-second – a feat that would be particularly notable against the backdrop of Ethereum suffering another network slowdown.

EOS members have been accused of attacking the Ethereum network before. A spam attack that Vitalik Buterin estimated cost attackers $15 million occurred in July; many blamed EOS for that attack, though no one provided any proof. Dan Larimer of block.one denied the accusations, saying EOS would not spend the required money to attack Ethereum, especially since, as he put it, “all it takes is CryptoKitties” to bring down the network.

Others speculated, perhaps more plausibly, that the traffic is the result of a game being played on the network – in this case, a dubious lottery-style game called Fomo3D, in which players bid on a jackpot. After each bid, more time is added to a countdown clock, allowing for additional bids. Ultimately the last bidder wins the jackpot.

While there are still no definitive answers about what exactly is happening on Ethereum right now, there is a depressing possibility that Ethereum, which previously reached the heights of its usage as a platform for buying and selling virtual cartoon cats, is now feeling its limits pushed by a game that is essentially a Ponzi scheme.