Comment More reliable than some other paper serving (Score 1) 185
Paper serving is not some super serious must be done in person thing. You usually do need to try to have a process server try to serve the papers in person. But when that fails, then it's good enough to just give it to a housemate or relative. If you can't do that, then it can be mailed. If it gets down to it, *the papers can be served just by posting a notice in the newspaper*.
Facebook has 'the message was seen', which is more reliable than a lot of these. If it goes into your spam then it doesn't get marked as read. And it's fairly obvious whether you've been active on your account or not - it's (hopefully) much harder for someone to fake being you on FB for six months without anyone noticing than it is to just register a mail address in your name.
The courts are used to dealing with all manner of tricksy dirtbags, so when they go into hiding mode, the courts go into more aggressive, more error-prone methods. This fits right in there. You can, of course, just lock down your FB account for posting - or use an app that doesn't mark the message as read. But FB users are more likely to be posting public photos of their crimes on FB than to fix their privacy settings.