Is it cheating if 2 players work together in four player (free for all type) chess?

I just played a game of 4 player chess where two players blatantly worked together as a team.

I know in 4 player chess it can sometimes be frustrating when opponents gang up on someone, but this was clearly something quite different.

One of them sacrificed a bishop and a queen so the other player could gain checkmate on one opponent, and then they did the exact same thing to me. They didnt take a single piece off each other, and once I was eliminated one of them resigned immediately.
When I asked if they were working as a team one of them turned the chat option off.

I can supply their names and a screenshot of the game in question if you wish.

It isn't that rare. I see this kind of obvious collusion* in maybe 5% of my free-for-all games. The idea might be to rig one's rating - you can rack up points very quickly this way when you collude to make sure you come in 1st/2nd in every game. In some cases, I think that it might even be a single person running two accounts simultaneously from two different browsers. Some people really have nothing better to do.

It's frustrating that chess.com doesn't allow us to block these players from matching with you in four-player games (using the block feature on their profile only prevents them from messaging you and so forth).

*Note that I am talking about the same phenomenon as the OP: while having two or three random players yell "everyone now gang up on blue!" is annoying, this is far worse. The players who collude in this way genuinely don't try to win once they have achieved their goal of eliminating their opponents.

this happened to me just now, it was super weird, they both brought out their queens early and checkmated the person across from me, and then me, supporting each other. 

Chess.com's wildly inconsistent approach to policing this is frustrating. I reported it last year and got four accounts promptly banned for match-fixing; I reported an identical case a few months ago and was given a dickish response by the moderator that "colluding in free-for-all isn't a violation of the rules." For now, I have mostly quit playing four-player as a result. Not worth it when the site refuses to just ban people who commit obvious abuse like this.

  Doesn't it fall under....."friendamies".?

I agree mb664. colusion in "FFA" or "solo" 4 way IS cheating. Since there are 3 modes to choose from in this .  That "modorater" sounds like a cheater herself. 

I'm sick and tired of this nonsense now. This is a reason I stopped playing 4 player. Cool concept, but its disgusting the length people will go to, in order to get a rating. In principle, you will never be a good chess player if all you are chasing as something as trivial as a cheating rating. 

I think it's cheating 

I too suffered in this situation my friend....Therefore 4PC sucks

This sucks (& yes, old thread) but what's the point of getting high rating by cheating? You'll just end up being outmatched in non-cheating games.

I think this kind of misunderstands the psychology of cheaters of all kinds on a site like this. It's not really like cheating at the Olympics - there are no massive financial or reputational incentives to use an engine in free online chess against typical woodpusher-level opponents. Getting a high rating isn't really the end goal here either; unlike at the highest levels of athletic competition where you can trick yourself into thinking that you "deserve" to beat your opponents, even via cheating, because there is very little variance between the top competitors at that level, random chess cheaters are mostly not doing it because they are so emotionally invested in winning games or watching their rating rise.

Rather, they're in it for the lulz: the immediate dopamine hit from the site telling them "You Won!", and especially, from the feeling of power that comes from being able to troll hapless non-cheaters.