Since I never knew that "www.paypal-community.com" existed, I checked the basics:

  $ nslookup www.paypal-community.com
  Server:         66.174.92.14
  Address:        66.174.92.14#53

  Non-authoritative answer:
  www.paypal-community.com        canonical name = ppl.lithium.com.
  Name:   ppl.lithium.com
  Address: 208.74.205.40

  $ whois paypal-community.com 
  Registrant Name: Host Master
  Registrant Organization: PayPal Inc.
  Registrant Street: 2211 North First Street
  Registrant City: San Jose
  Registrant State/Province: CA
  Registrant Postal Code: 95131
  Registrant Country: US
  Registrant Phone: +1.4083767400
  Registrant Phone Ext:
  Registrant Fax:
  Registrant Fax Ext:
  Registrant Email: hostmaster@ebay.com

  $ whois 208.74.205.40
  NetRange:       208.74.204.0 - 208.74.207.255
  CIDR:           208.74.204.0/22
  OriginAS:
  NetName:        LITHIUM-NET1
  NetHandle:      NET-208-74-204-0-1
  Parent:         NET-208-0-0-0-0
  NetType:        Direct Assignment
  RegDate:        2007-02-09
  Updated:        2012-02-24
  Ref:            http://whois.arin.net/rest/net/NET-208-74-204-0-1
  OrgName:        Lithium Technologies, Inc.
  OrgId:          LITHI
  Address:        225 Bush Street
  Address:        15th floor
  City:           San Francisco
  StateProv:      CA
  PostalCode:     94104
  Country:        US
  RegDate:        2007-01-04
  Updated:        2014-02-25
  Ref:            http://whois.arin.net/rest/org/LITHI
  ...

And of course: http://www.networking4all.com/en/support/tools/site+check/re...

Many pages on paypal-community.com have a "Powered By Lithium" banner, so they seem to be the folks who wrote the "community forum" software.

http://www.lithium.com/

And they're mentioned in the paypal privacy policy:

https://www.paypal.com/uk/webapps/mpp/ua/privacy-full