http://tvtropes.org/pmwiki/pmwiki.ph...oisonousPerson
A character that carries a disease, emits radiation, or is suffused with a deadly poison, but is immune to it's effects, meaning that they deal damage or kill with just a touch.

I've heard it suggested that this character type is unsuitable for a player character, and that it's not -really- a curse for any PC, who will just use their powers to kill things without really suffering from any drawbacks. On the other hand, I've also heard that it's a crippling disadvantage, and there's no reason anyone would WANT to play a character set up like this.

So, I wanted to ask: What do you playgrounders think of this? Would you allow someone with this sort of power into your games? How would you mechanically represent it, in any system you care to mention? Do you think this could be an interesting source of drama, or is the trope overplayed?