Someone/anyone

I found this unhelpful answer using Google.

It's unhelpful because like most people bringing these style questions comparing two similar sentences that ultimately mean the same thing? Stop overthinking it. Like the alleged answer provided above? No one really gives that much thought into these sentences if they're speaking casually and direct.

The only one who would care is some stuffy philosophy professor who has way too much time on his hands and he genuinely believes these questions (not inferring to your specific grammatical question) need to be answered for the sake of humanity.

Long answer cut short? There really ain't any discernible difference between the two sentences.

They are in that context, but not all. You wouldn't say, "Anyone broke this dish." or "Anyone left an obscure message on my machine.", for example, but I'm sure you know the difference between the two words.

Thanks for answering my question! someone is more specific while anyone is more general, right? I just got confused in the context I've provided because one of my friends said any is negative whereas some is positive.

For example: I don't know anyone who plays this game.

I know someone who plays this game.

However, I'm not entirely sure about this because in the sentence you've provided, it would be correct if we are going to add the word 'can', right? "Anyone can leave an obscure message on my desk."

I'm not really clear what you're asking, Rox111.

Of course you can use the word 'can' with either word.

"Can someone - anyone - help me? Any of you bozos standing around will do!"

You use 'someone/somebody' and 'anyone/anybody' the way you'd use 'some' and 'any'.