Front-Running

Front-running is what happens when you check whether a domain is available, decide to sleep on it, and come back the next morning to find it registered. The accusation is that someone with access to the search logs grabbed it first.

The famous case was Network Solutions in 2008, which started registering every domain searched on its site and holding it for four days so the searcher could only buy it from them. They called it protection. Everyone else called it what it was, and they stopped after the backlash.

It's rare at reputable registrars now, and most of the "someone stole my idea" stories turn out to be coincidence or an expired name coming back around. But it costs nothing to be careful. If you find a name you want, register it before you tell anyone, and do your bulk availability checks at a registrar you trust.