The ratings I generate for online poker cheating are derived statically from various sources of data and information that I accumulate from both experienced online poker players and statisticians who continuously sort and analyze data sampling millions of hands. I cannot guarantee that my rankings are exactly true to the online poker world at any given moment, as online scams usually develop with startling rapidity as we have certainly seen during the past few years. However, in the long run, you can place a good deal of faith in these rankings as they will pan out even with the sizable deviations due to large scale cheating scams. For instance, Full Tilt and Ultimate Bet were all very risky sites to play on, but only for a short period of time. So the long term result of those scams on these sites would not prevent any of them from appearing on my Top-10 list of safe sites. Many sites that tend not to appear on the list are those that experience constant episodes of cheating, mainly in the form of collusion and bot play, not inside scams as was the case with Absolute Poker. The recent spate of account selling super user scams also had a minimum effect on the overall safety rankings on this website.
As far as hacking to see opponents' hole cards goes, this is very rare, at least without inside employees being involved. Any cases of this kind of cheating will be immediately posted on my main blog.
If you have a question about any online poker or casino website, do not hesitate to e-mail me about it, and I will provide any information I have about the sites in question.