It really isn't "decentralized" if ISP's are controlled by corrupt institutions that let some huge players get away with the most egregious acts
Here is a good definition of what decentralised actually means to me, in terms of crypto-currencies: you own the true value unit of the currency, not an IOU saying you're owed some amount. No one can take it away from you, barring a 51% attack, or equivalent systematic failure.
There is a different kind of 'decentralised' that people will sometimes confuse with the above one, which is the HSBC model: HSBC has many branches, throughout the world, therefore it is decentralised.
These two definitions of the word are very different.