Can you assume that all inputs to a Bitcoin transaction are controlled by the same person?

Question

When you are looking at a Bicoin transaction in the block chain and it has inputs from multiple addresses is it safe to assume that those addresses are all controlled by the same person/organization/wallet software?

Here is an example of a transaction with 31 different input addresses

https://blockchain.info/tx/a6bffa6208c72412399997b0c504670662e259fd5ba50128d0e2823b739bd18b

If I have definitive proof that one of those addresses is associated with someone can I infer that the other 30 are as well?

Answer 1

No.

In practice, it is likely, but in several more complex use cases, transactions can be jointly constructed.

For example CoinJoin implies combining both inputs and outputs from multiple people together into a single transaction to make it less obvious which outputs belong to whom.