Thank you both for your responses.

I have no problem sharing my email and data with my matches, my only concern is what Gedmatch can do with the raw data. I just want to be sure that something is in place that would prevent them from selling/giving it (their whole data base) to a 3rd party (such as researchers, advertisers or another genealogy company).
If it was just my data I wouldn't be concerned but since I am custodian of other family members tests I have to be careful.

Thanks for their email address. Hopefully they can address my concerns and I can join others in using their wonderful "tools" since Ancestry doesn't seem inclined to provide any....