Researched. It is almost most certainly someone spamming up the chain. Unless you want to tell me that we have *genuine* users with multisig addresses that are dormant for months and suddenly create over 1k transactions each during those two days? 
Let's assume that someone, or some entity, starts openly sending a huge number of transactions (on the order of many thousands) with hefty fees between just two addresses. Will miners continue to confirm these transactions when it becomes absolutely clear that exactly these transactions are causing the congestion? Or would they choose to ignore them altogether even despite the fees which might be higher than fees of most other transactions?
In other words, could there be a blacklist of Bitcoin addresses?
Miners will consume the fees gladly if two people are paying over the odds to play Ping Pong with their bitcoins....
Under the current economic law the persons who pay the most go first and I guess they will run out of money (btc) before the miners will say no thx...
If these Bitcoin Ping Pong players also happen to be miners (or just one miner with two wallets), they might never run out of money at all. I guess that would be a working (allegedly) concept of perpetuum mobile as it can be applied to Bitcoin payments. So it all inevitably and invariably comes down to some rogue miner (a group of miners) wanting to artificially raise fees, earn money, and make it look like Black Friday...
What do you guys/gals think, is it feasible (possible)?
Its very possible that miners could be involved in this game...
Nobody will complain while he is making a few thousand dollars per hour from inflated fees....
