Private Equity

I am the only person wondering about these private equity funds that are buying up some of the largest companies in the United States? Today it was announced that Alltel will be purchased by a private equity fund for $27 billion.

I am not saying that these purchases are necessarily bad, but they certainly seem suspect to me. I am going to have to do more research on the topic and update here periodically. I guess the biggest question that never gets answered is who is providing these huge amounts of capital. Are they foreign investors? Hedge Funds? A combination?