I totally disagree that these sites are garbage. Many of the trees may be garbage but that is not why I subscribe. The number of records to be found on these sites is far beyond what I could hope to find w/o them - let alone pay for copies of them from somewhere. Death records alone for everyone in my tree would be beyond my means. And my tree is not that big! Yes, there are plenty of incorrect transcriptions. Ancestry - I assume - still uses non-English speaking translators saying they are less likely to make assumptions - i.e. cheap labor. I do not know about My Heritage. There are also the people who claim your family and add incorrect alternate information to deal with. On Ancestry I always correct misspellings and transcription errors as well as people making wrong claims.
Family Search uses native speakers - you can help index for them if you are bored! If I remember correctly they go through 2 indexers and a 3rd arbitrator per record. I still have had some of my indexing corrections overridden even though I know them to be correct as I researched other records for the family to be certain.
I do not put my info online but two cousins I sent to have - w/o asking. I am confused by what you mean by, "My data has been leaked by two such companies without my permission." Leaked from where? Is this public data like birth and death dates?
I was very fortunate about two weeks ago to come across a record on My Heritage that provided part of an answer as to what became of my grandfather, Henry Schwarzbaum and I have been searching for him for almost 20 years.
Carolyn Lea (Schwarzbaum)
Schwarzbaum : Posen, Lewinsohn/Levison: Elbing, Rothschild: Hamburg?, Basch: Poland/England