And how many of these emails were unflattering remarks by the competitor or panel manager?

This whole article reads like some spastic marketing douche who is running too hot to consider his own actions and how they reflect on his company. Not to mention fixing typos and poor phrasing in his company blog.

Unprofessional is the word.

If I control a the marketing resources of a high profile brand (He mentions Pepsico, so I'm assuming the target is other large companies), I'm not sure I want to be associated with a business that pulls stunts like that.

Part of it would be avoiding guilt by association for being unprofessional. I also wouldn't want backlash if Virools methods turn out to be complete sleaze and something crazy like getting all of my Facebook likes or youtube views reset (viral equivalent of being Panda'd?)

Even though its not the event companies fault, why would anybody want to pay to sponsor a session when you can just drop in and pass out literature for free?

Can't say I've ever seen someone banned for doing something like this - and events seem to always have someone doing something controversial - so I don't see it happening. More likely a "stern talking to" as my Dad would say. Imagine if Virool got huge and came back the next year wanting to by a 20x20 booth - I doubt anyone is going to stop them.

Ultimately, that's why people do controversial tactics - little downside to doing them.