What do you do if there is a trade accepted in your league that is clearly not a fair deal? What if one person is taking advantage of another, newer fantasy player?
Something like Joey Votto for J.D. Martinez. Man, have you seen Martinez' numbers in the minors! That guy is going to be a superstar!
Or, how about this... What if you see one of your primary competitors is getting stronger and you'd really like to block the move, even if it is a reasonable deal? Hmm... that is a tricky one, isn't it?
These issues fall into a grey area based purely on the opinions of other people. So many people are completely against vetos of any deals. Period. Other people are almost always against vetos. Others don't have an opinion.
Me? I'm glad you asked. When it comes to vetos I have two questions: (1) Was there collusion?; and, (2) What is allowed by the rules?
That's it. If there was collusion - automatic veto. There should never be collusion in fantasy sports. It ruins the fun for everyone when two teams conspire to turn one of the two teams into Voltron super-team.
Okay, simple enough but what if you would just like to block a nice move that a serious competitor is making? A lot of people say you shouldn't veto any deal that is even close to being fair. They are adamant about this. I say you should do whatever is legal and ethical to win your league. If you have a vote and you don't want the deal to go down, go ahead and vote against it. In most leagues it takes somewhere between 4 and 8 votes to pass a veto, so if the deal is close to fair than your vote probably isn't going to be enough to get the veto done. So, no harm no foul. You gotta try, though.
I did say that you should do what is ethical, though... Never ask any of your leaguemates to join with you in the veto. That is tantamount to collusion and just not cool. Cast your vote, keep your mouth shut, see what happens.
Then, go and work on a deal of your own.