Soft playing in high stakes online NLH

[doubleup]

Somewhat obscured by the multiple entry cash confiscation story, it has also become apparent that various players in the 10/20nlh in Stars and possibly elsewhere have agreements that they will checkdown when heads-up.  Pokerstars apparently have no problem with this.

I cannot understand this.  How can such an arrangement not affect other players?  Can anyone provide me with an example of a hand situation where such an agreement would come into play that would not afford an advantage to the soft-players that is not available to an "outsider"?  I include in my definition of advantage the comfort of knowing that at some point (even if it is making up the sb to co-conspirators bb) the pot will be checked out.

[Nem]

I've read on Tillerman's blog that he and Twin Caracas soft play against each other all the time

[AndrewT]

In a cash game with two players, I don't suppose it has any real effect on everyone else what they do with each other's money. A tournament is different though.

[The Baron]

At least 3 or 4 times on seperate occasions in Vegas at WSOP cash tables I got talking and drinking with some Americans and some Irish lads.

Almost everytime I got into a pot with one of them and no one else was in the pot they ask aloud "do you wanna check this down?" to which I would say yes not wanting to be rude.

My opponent would then tell the dealer we were checking it down and to deal it out. Being in their country and not knowing all of their house rules (like the Mississippi straddle, buying the button, missing the blinds, etc etc) I just thought it was all part of their game.

Everyone on the table was fine with it on all occasions. Is this different to doing it online?

[doubleup]

Maybe I'm picking up what these guys are doing wrong, but let me try an example

Me in cutoff with    - I raise

Tillertwin in BB  reraise

twinTiller in cutoff    

Tillertwin in BB  call

Obviously I have to think twice about raising trash from the cutoff - does twinTiller?

How does that not affect the small blind and button who will clearly face more aggression when in between the twins?