Why would people attack this coin?
Do they target all scrypt coins and try to make double spend attacks?
Or is it noble that get a special treatment for some reason?
From all the puzzles that i collected, i think that someone has something personal to Rofo, maybe after reading the PDF's and Rofo's strong points there.
So that person(s) wants to prove that Rofo's coin fails (and in that way prove that his opinions are also wrong).
Which, as we all know, is very childish.
So, as they form maybe a group with LOT of btc (look at extraction. also consider that only the last attack should have costed easily more than 12-15 btc [...]
This exactly what I think,
The first attack was profitable because mintpal had 3-6 confirmations for nobl deposits so they could double spend or whatever they do with 51%,
After mintpal raised it to 999 conformations attacks become useless (not profitable) and that is why I must assume it is something personal against ROFO/NOBL.