Anyone can threaten with legal action over anything. Doesn’t mean their case has merit. How big companies abuse trademark and copyright law doesn’t actually mean that’s how the law works.
There’s a 20-mile radius around Mattoon Illinois where the “Burger King” trademark is reserved for a one-outlet restaurant that’s used the name since the 1950s - before the big chain became a nationwide thing. In Australia, the Burger King company operates as “Hungry Jack’s” because a completely different company held a the nationwide trademark on “Burger King” before the multinational set foot in Australia.
For a company that does an international business by Internet, then the regional domain might be the Internet. You could call a physical event at a coffee shop “Knit with Friends” and there would be no dilution of Zynga’s trademark - no one is going to think Zynga is associated with something as pleasant and genuine as actual humans getting together to knit and chat.
