It seems that the appropriate process for this issue would be suing the registered owner of these domains (Whoisguard), which is what they're doing now - and a court of competent jurisdiction will be ruling on it.
Facebook doesn't say exactly what they are seeking, but that is one possibility. However, this PR piece seems to be accusing Namecheap of doing wrong- and it appears that Namecheap is entirely in the right. If all Facebook was doing was seeking control of the domain name, and they didn't make this accusatory post, I would agree that they were following the proper process.
