It is being reported that this poster is being seen around Wondercon:

The poster prompts you to go to webbedmenace.com. When you go to the supposedly anti-spiderman website, you get this viral video:

You can also submit your sightings, which has obviously led to funny and ridiculous cosplay such as this:

Also if you get a kick out of things like this, the phone number on the poster is real. It is a taped message prompting you to go to the website to help combat the Spiderman menace! Call (877) 651-8503 for some laughs.