I've heard horror stories of accounts ending up implicitly linked (as in when account X gets banned, accounts Y and Z do as well because Google has determined that they are all controlled by the same person).
To be fair, in all the stories I've heard, Google was correct about the linkage, but it means that one person using 3 accounts gets less benefit from not linking them than one might think.
To be fair, in all the stories I've heard, Google was correct about the linkage, but it means that one person using 3 accounts gets less benefit from not linking them than one might think.