You sign in with your email address, so technically, if you have multiple email addresses, then you can have multiple accounts. I mean, how would people really know? I have a hard enough time keeping up with this one, so no thanks to the alts. :-)
It's been a hot topic because (I'm guessing) people are creating multiple accounts and using them for trolling/downvotes or even upvoting their main account's memes. But like phantasmemegoric was saying, it seems like it would just be a hollow victory. If my memes aren't good, then they aren't good. I choose not to have alts. :-)