earlier mql5 allows all kind of account for signal providing as well as demo acc.
by the time the have upgrade some condition which improve the quality of signals. still there are some signal providers( i suspect those are working on broker or their close buddys) those are manipulating the signal with past data. recently i found some signal those have 6-7 month of history but added just 1-/ months back with huge growth.
and after analyzing there trade history found unrealistic data. those are made within 1/2 days which gives them huge growth % to catch the subscribers.
in mql any one can add account any tie and without analyzing those past data they counts. but most of reliable social trading service / broker dont allow past data. few of them dose but they take at least 1 week to analyze the past record then approved if they found any suspicious thing. but here in mql5 ppl are taking the advantage of this and making thousand of dollars for few months and disappears. i dont know to whom i should write this so that they can check the fraudulent past history and take some initiatives to allow past history under sertain condition or safe option is not to allow any past record.
Writ to service desk and they will respond back to you.