Spam... Spam pisses me off. It pisses everyone off. And the sites where I see it strike the hardest are those with open APIs. Sites like Twitter, Facebook, Youtube, and others are simply too open for their own good, so to speak.
One of my favourite social networks, Hatena Haiku, had to shut down their US service because of all of the Russian language spam that flooded the community. Almost all of it was phishing attacks in the form of unregulated soccer streams, with a few spear phishing attacks peppered throughout.
I see similar spam comments on YouTube, often imitating the very channel that owns the video they're posting the spam on. Channels like Markiplier and Game Theory will see giveaway spam posted in video comments, using their own names and avatars.
Then there's the Twitter spam. It's on a completely different level, using keyword searches to tag both users and tweets alike for replies and follows. Most of these spam accounts look like real accounts, except that they do nothing but throw out generated content. In most cases, the link in their profile leads to a phishing attack meant to hijack the user's account through OAuth.
The problem is the whole "public API access" issue. I hate to say it, but the only way to severely reduce the spam is to close the unrestricted access to those APIs. Put up more barriers to get tokens that allow for that sort of access. Even a mobile number doesn't seem to be enough.
And yes, it's completely possible for a person—or group of people—to be employed for this purpose. I'm fairly certain that's what happens on YouTube, Yahoo Groups, and many PHPbb forums. That's what moderators are for, though.
And with that, I'm done ranting.