Quote from: johoe on December 04, 2016, 02:38:17 PM

Okay, amacllin noted these transactions already in August:

https://bitcointalk.org/index.php?topic=1575527.0

But nobody has a good explanation why these exists.

ok i see what your getting at now. i thought u were asking a noob technical question. sorry.
seems your asking a psychological/social question

here is the thing.
knowing why/who wants to fund a certain address or adds a certain address as one of the multisig qualifiers is like asking why/who wants to buy banana's from walmart.

no one will give a definite answer. but your asking the wrong questions

for instance when it utilises / spams
https://blockchain.info/address/1BgGZ9tcN4rm9KBzDn7KprQz87SZ26SAMH
the KNOWN address where the privkey is literally not a long garbled seed of words/hex characters but simply "1"

that particular address had a tag on blockchain.info advertising a scam/virus.

in short it was trying to advertise a "bitcoin manual mining helper" scam

so someone used their multisig added the scam advert address.. spent some funds where the known address appears in the tx as either an input or output. then put the rest of its funds back into another multisig.

many people have done this, where they either tag their own address with something (scam/business/service) and then send small amounts
to another address. or send amounts to another address thats been tagged

though this is not the definite answer it does explain things.

another explanation is that the person with the multisig is simply testing things. so doesnt actually require a third address involved in a multisig. and just threw in the known address just for the sake of it.

its not a security risk to that person because the other addresses secure the multisig. a hacker still needs atleast one of the other private keys to break the multisig. so cant break it just looking at blockchain data.