J&R Palisade Collection John Swanson Left a message on my cell phone....Yeah hi, my name is John Swanson Im a process server with J&R and I'm driving around here. (threatening me into thinking he is in my neighborhood) I've got a court Grand Prarie , Texas

Please file a police report.  The phone # is still active and goes to a John Swanson.   The # is a cell phone provided by Cellco via Verizon.   It looks like he has stated he is with multiple collections agencies - likely he is not with any of them and is a scammer.   His # also shows up on some old Craigslist ads for renting a student apartment in Buffalo NY.
If you file a police report they can at least subpoena the records associated with the phone # to pursue charges.  Not only has this guy threatened another poster per the link you provided but there is another report #  857302 (851182)    It is likely he has done this to others and it's not being called out separately becuase they are blaming the collections company in their report title not the individual.
Please file the police report and then post back here on your progress.  I will also update if I find out anything more on my end.

It is a violation of the Fair Debt Collection Practices Act for a debt collector to pass himself/herself off as anything other than a debt collector. Inform them that you are aware of those rights, and are prepared to seek council and to force them to award you damages of $1,000.00 per violation. I can pretty much guarantee the harassment will stop after that.

I used to be a process server.  When serving court papers, the person being served is never asked to sign anything.  After I served a party I filed an affidavit with the court attesting to the fact that I had served him.  I never once telephoned a party to warn him I was on the way.  Process servers count on surprise.

This bill collector most likely wants you to sign some sort of admission that you owe the debt he is trying to collect.  My advice: agree to meet him in a public place with witness present and some muscle waiting in the wings.  When he arrives, ask him, "Are you a process server?"  Then ask, "May I see your court-issued ID?"  If he cannot produce the ID, signal your muscle to come in and beat this jackass into a blob of protoplasm.

I never called him back in all the million times that he has called me or my family.  He called my son a couple of hours later, but this time said he was down the street from my previous home.  He told my son that he had a summons to serve me.  My son asked why was he called.....and his respond, " you are listed as secondary contact for serving her summons." What a physcho!  My son did not release any information to him, of course.  Mr. Swanson has also contacted other family members including my mother on numerous occassions causing her to become ill because of his threatening harrassing calls and DEMANDING updated information on me.....she finally told him to go F$#@! himself!  This mentally unstable individual is playing with fire and with people's lives.  This game of threatening manipulations is going to backfire! All I need is for him or any peculiar individual to show up in my new home and trust me, I am not one to f#@! with.  I have never had any issues with the law but if you threaten me and hurt my family.....well, I will just leave it at that! Come to find out, I am not the only one, this person has even threatened others  http://www.ripoffreport.com/credit-card-fraud/palisade-collections/palisade-collections-threats-8dfc0.htm

That's a new approach. I would NOT have returned the call. See if the guy shows up anywhere.

Professional servers NEVER call ahead.