The World Cup is in the news and so are the "Brand Fascists". FIFA, the international organization overseeing the world cup, is aggressively protecting its sponsor's brands. So aggressive are they that over a thousand members of the Dutch contingent watched one of their latest matches in their underwear because of a non-sponsor beer logo on their lederhosen.
No joke! A Dutch beer, Bavaria, produced these patriotic orange shorts in a marketing push in the run up to the world cup. On June 16th, as Dutch fans lined up for the Ivory Coast match, FIFA ordered ticket holders in the queue to throw their shorts away before entering the stadium.
I really wonder if Anheuser-Busch's Budweiser marketing team (Bud being the official beer sponsor) was closely in the loop on the FIFA decision. If they were, then that's a really bad call on their part. If not, they should be complaining as loudly as the fans to try to set things right.
If you're not providing the event free to the public, sponsorship should only mean prominent name placement, not a ban on competing messages. The repercussions of being perceived to be "brand fascists" must far outweigh any effort to stop brand dilution. The thing to remember is that brand expressions by the attendees wearing/carrying/consuming competing products are usually an indication of personal preference, and not a systematic attack by another brand.
When you start tangling with restricting attendee preference expressions, you're in essence trying to dictate personal behavior - which wasn't the core reason you sponsored the event in the first place. Even if another brand has been smart enough to piggy-back their message on something that an attendee might wear, the downside of negative customer experience isn't worth it.
So, be a "brand fascist", and be remembered sharply negatively as such by the people both directly and indirectly touched by your policies. That's in sharp contrast to the soft, positive message you were trying to achieve by the sponsorship.