To show how ethereum had made it's language turing-complete Vitalik in his white paper gave this example:
"To show the motivation behind our solution(i.e using gas), consider the following example:
A financial contract works by taking the median of nine proprietary data feeds in order to minimize risk. An attacker takes over one of the data feeds, which is designed to be modifiable via the variable-address-call mechanism described in the section on DAOs, and converts it to run an infinite loop, thereby attempting to force any attempts to claim funds from the financial contract to run out of gas. However, the financial contract can set a gas limit on the message to prevent this problem. "
- What are the "proprietary data feeds" he is mentioning about?
- "An attacker takes over one of the data feeds,..." how does the attacker takeover(control) one datafeed.
- What kind of datafeed is he mentioning about? Is it a number, address, contract or any other thing?
I am new to ethereum so please explain in plain english.