Things that I don't think have been mentioned that banks may very well be looking at include -- where you live (I would think that people in MI, OH, CA, and other hard hit states are going to suffer more at the hands of card companies than people in ND, VT or other states that are not suffering the effects of the recession as much), what the banks show (not necessarily what is the actual amount) of you HHI is, any changes in your spending patterns not only on their card but on other cards as well, where you pay them from, do you pay online, over the phone, or by mail, do you access their website often, do you acces it using Quicken or other financial software, and so forth and so on.
The banks can measure all of these things (and would be remiss if they did not) so I figure that any and all of them could factor in to these decisions. If I were a bank, my ideal customer would be someone living in a low unemployment state who has had a mortgage for 10 to 20 years with a perfect payment record, where real estate values have fallen far less than the national average, who regularly monitors his/her account using some kind of finanacial software package, who has not changed jobs recently, who makes a consistant pattern of many small to medium purchases from the same stores, who makes regular payments of an "appropriate" size, who does not yo-yo a balance. In other words, I would want predicability and indications of security. If I don't get it, then increasing rates, decreasing credit, etc. would be a possiblity to compensate for that lack.
Now, you may feel that you are within your means and well able to meet your credit obligations and you have done so. That does not mean the banks feel the same. And, since the banks tend to get burned unless they anticipate problems, as far as they are concerned, it is better for them to err on the side of caution.
