Skype
  Min: 6
  Max: 32
  Can contain: a-z A-Z 0-9 . , _ -
  Other: Must start with a letter

Twitter
  Min: 1
  Max: 15
  Can contain: a-z A-Z 0-9 _

Facebook
  Min: 5
  Max: 50
  Can contain: a-z A-Z 0-9 .

Steam
  Min: 2
  Max: 32
  Can contain: a-z A-Z 0-9 _ -
  
YouTube
  Min: 6
  Max: 20
  Can contain: a-z A-Z 0-9

Twitch
  Min: 1
  Max: 25
  Can contain: a-z A-Z 0-9 _

GitHub
  Min: 1
  Max: 39
  Can contain: a-z A-Z 0-0 -
  Other: Can not start with a dash

reddit
  Min: 3
  Max: 20
  Can contain: a-z A-Z 0-9 _ -