Still wouldn't consider anything that has happened to be an attack. Most likely just early investors nicehashing legitimately.
However there is concern for attack after Caliber is listed on an exchange because would be 51% attackers could rent the power required. Will have to monitor the network hash.
One good option is to switch to a mining algorithm where there isn't enough hash to rent for 51%. However lots of coins are technically at risk right now by this method and don't have any issues.
The lower the nethash, the bigger the risk and lower the cost of attack.
I will dedicate some time to working on this. I'd rather have the piece of mind.
Legitimately nicehashing would result in consistant nethash over a prolonged period of time (adding to network stability).
There is consitant doubling of hash power on the official server for short bursts (which looks like early investors trying to grab large amounts of coin... with over half the network hash rate on their side).
I'm still contributing my rig to the network, but those 'early investors' are not in it to help the network.
I don't know if there is any real way to deal with this issue other than get more on board to mine.. but I hope you are looking at ways to at least prevent massive spikes like the ones we are seeing often.