If you have enough rep to get the association bonus on one site, then on any site which you don't yet have a profile on, you can upvote or flag (sorta) comments as many times as you like. Normally, if you vote or flag a post, that forces you to wait 24 hours to recreate your account, which is a barrier to abusing your ability to vote or flag posts multiple times. However, for comment flags and upvotes, they do not cause to you need to wait the 24 hours, so you can just upvote over and over by deleting and recreating your account.
Flagging is slightly different: You can create an arbitrary number of mod flags, however other flag reasons will be removed upon account deletion.
