Nerf the damage. As of right now they can two-shot nearly any champion- unless the target has bought 900 credits worth of items and the sniper lacks a damage talent. I think they should still be able to two-shot champions, but if at least one shot is a headshot. Their basic attacks taking down the average champion in two hits makes coming out of cover, even at full health, to do some damage a risky move.
And for those who think flanks are a good enough counter, they die in two hits as well and a decent sniper can drop something like a flying Evie with little effort.
When I bring this idea up at the post-game lobby the only people to object are the sniper mains.
Bodyshot-bandits make every1 cry plz fix