In short, Greece has already been taken.
The key point to note is that money does not have any value until it gets exchanged for either goods or services. Until that exchange happens money does not have any value whatsoever; it is merely a promise and creating promises costs literally nothing. Every country (except for those in currency unions, yes, Greece) can create endless money supplies at no cost because money as we use it today does not have any value.
Goods and services have value, not money. For anybody that happened to live through hyperinflation times or even quantitative easing periods which is happening as I am writing these words as ECB launched 1 trillion (!) QE program, it's obvious how burning money can be.
ECB is not after money as it can easily create endless money supplies, just to mention, quantitative easing.
What ECB is after is control.
ECB wants to control country's domestic matters and make sure that ECB, or wider, the whole banking sector, maintains its supreme position in the country's economy.
Both Lucas Papademos and Mario Monti (yes, Italy) have strong ties to the biggest banks, yet they were supposed to represent their country's interest. Whose interest do you think they were defending? And these two guys aren't even an exception.
So for ECB, the main player in the Euro currency union, it makes sense to keep buying Greek bonds because it costs them nothing and, most importantly, assures Greece stays in Euro Zone which in turn means that ECB essentially controls the country.
The only challenge is how long other countries who are not directly the lenders, will tolerate such a scenario because they are the real losers.
As predicted in my answer, ECB just confirmed that it will step in and provide liquidity for Greek lenders. ECB did so because it is in its own interest to keep Greece in Euro zone regardless of how much money they require to maintain liquidity as creating money does not cost anything. Greece will only leave Euro zone if 1) decides to do so 2) other Euro zones countries will kick Greece out.