My Sympathy for such things is in inverse proportion to the size of the corporation. As in the smaller the company, the greater the chance I will sympathize. Also, if the company is run by a "Human" instead of rotating CEO's which only think in terms solely based on revenue projections.
Visa and Master card, solicit very little sympathy for me. Amazon has me a bit torn, as it is a first generation company started from nothing and still led by it's founder, as in it's not just a machine without a soul yet. The Bezos guy seems to be an okay guy, so I'm guessing it's government threat.
Paypal/Ebay, I don't really care, it's a soulless hunk of machine now, they switch CEO's and key staff more often than one changes cars. It just exists to milk cash. There is nothing wrong with that, but I don't feel sympathy for old tires either.
Fundamentally, are these attacks wrong. Well, I guess that depends on how intertwined the companies are with government. VISA and Mastercard undoubtedly are more entrenched than ebay, and amazon probably less so than ebay.
If the premise is to attack the government through its front facing corporate partners, then they should be attacking GM, AIG, ETC.... it would be more directly applicable.
On a scale of 1 to 10, I'd say it's a 2 on the wrong side.
However, I think these attacks are unhelpful overall, they are entertaining, but they destroy the public sympathy for wikileaks. Everyone hates seeing a little scrawny nothing getting beat up by the big kid. Now, they don't have that sympathy factor anymore. It would have been much better to have the government attack, and attack, and attack, while wikileaks struggled to remain up, that looks desperate, and not like a legit war against "rogue" leaker/hackers/.
Also these are Denial of Service attacks, they do not disrupt any real functions of mastercard or visa. The don't run the card infrastructure on there web facing server. It's like turning the lights off on the Wal-Mart sign, while customers keep going in and out of the store. People notice, but it doesn't weaken, nor change anything. It will stop in a few days, there bandwidth bill might double for the month, and at the end, dozens of people that are participating will be tracked down and given large fines and or jail time. I'm 100% certain the government is actively working with ISP's to try to gather as much info as possible.