Use tools like Webex/GoToMeeting/OCS where you can have an integrated A/V meeting and use local telco numbers to control costs. Be aware about the telco plan of the vendor (included or not and at what cost per minute). Webex used to charge for the telco minutes but I don't know what they do these days. GoToMeeting is free as far as I know but check to make sure.
Set up a collaboration environment like BaseCamp (if it's for Project Management) or MS Team Studio, Atlassian JIRA/Confluence if it's for development work.
If possible implement a way to easily work on documents together (either in-house or externally with something like Google Docs/Office 365 depending on what's allowed by company security policy).
Heavily promote the use of these tools and train people in effectively using them. Some people have difficulty starting up with these tools and end up not using them to initiate anything.
Blizzard first gets you intimidated by their figurative muscle, before the Don walks up to you, making you an offer you can't refuse?
Basically Activision Legal fires off the first shot before people with real brains realize the potential for something like this. The people with the brains probably did not know this existed before the C&D became news.
8 Catfish = 1 Octo-puss