It's already established that they are alts, that's not illegal on this forum. It's only illegal if they are joining the same sig campaign at the same time or abusing bounty campaigns.
I'm quoting the original post being referred here in full [below], just for the sake of added context. If I may add, aside from what yahoo said, one that's also not allowed is to add one's main account into alt's their trust list [on this case, I'll assume Haunebu is the main and 3kpk3 is the alt], though it's ok to add your alt to your main's trust list.
[...]
- It's okay to include your alt-account on your own Trust list. This means you trust the feedback you left from that account. [...]
- Don't include your main account from your alt account(s). This could influence DT1-voting, and although that's not part of this guide, it's bad
[...]
Username: Haunebu