How Blanket parses information (depth)

Ok first of i'm going to assume your familiar with the http/https protocols, both form/post,get-data etc. Simply writting a winsock, or inet, to the resource in question is simple, creating a method for finding working resources or parsing it is a little bit harder but not by much so i'll explain.

i wanted to be able to verify if someone had a yahoo email now how would i do this? well there is a few ways. i'll elaborate:

#Exploit an email sendback/confirm form (not subtle often rated)
#Dictate existance from a network login fingerprint(cumbersome)
#exploit a 'Does email exist" mechanism
#exploit a "in profle/*" que
#exploit simple static url /*/ que
#use existing search by method
#using member only searches (50% success most sites security)

here i'll show using a yahoo 'is available' mechanism,
DoEvents
profilecheck = Inet1.OpenURL("https://edit.yahoo.com/membership/json?PartnerName=yahoo_default&RequestVersion=1&AccountID=" & Text1.Text & "&GivenName=&FamilyName=&ApiName=ValidateFields&intl=us&4737863")
If profilecheck = "" Then
Me.caption1 = "No Connection/Error"
End If
If InStr(profilecheck, "PERMANENT_FAILURE") Then
List1.AddItem ("http://profiles.yahoo.com/" & Text1.Text & yahoo)
List2.AddItem (Text1 & "@yahoo.com")
End If

StatVar = Inet1.OpenURL("http://opi.yahoo.com/online?u=" & Text1.Text & "&m=j")
If InStr(StatVar, " NOT ONLINE") Then
yahoo = " -Offline"
ElseIf InStr(StatVar, " ONLINE") Then
yahoo = " -Online"
List6.AddItem "#----Yahoo online " & Now & "(!NOW!)----#"
List6.AddItem (Text1 & "@yahoo.com")
End If

that right there is an example of how blanket finds a yahoo account, and wether it is online first using the username as a var in the data to be outputted
https://edit.yahoo.com/membership/json?PartnerName=yahoo_default&RequestVersion=1&AccountID=" & $USERNAME$ &"&GivenName=&FamilyName=&ApiName=ValidateFields&intl=us&4737863

the information will be decided if it's a failure then it means the account exists (means failure of account availability) so you can know even if the /profile/ is ghosted (some yahoo accounts have ghosted profiles) next the is online? is dictated by http://opi.yahoo.com/online?u=" u= $Username, if the outputted data = Online then the person is on, i just tell the form how to percieve and parse the data. simple, so simple.