Who are TransUnion?

PoGee

I set up accounts with credit karma and Experian a few years back and logged on again recently.
Experian now only give a credit score on their free account. Credit karma show soft and hard searches as well as a credit score.
On CK, there are multiple soft searches carried out by them under the heading credit karma (Ls)(CrApi). They do these on a weekly basis. I have no loans or mortgages. My credit card limit is £3000, if which I rarely use more than £140 of. 
When I emailed CK, they said they do the weekly soft searches on behalf of TransUnion. 
Are these weekly soft searches normal or should I be concerned?

molerat

TransUnion are the other major CRA.  You have signed up with CreditKarma who then do a weekly soft search on TransUnion to provide you with changes to your file as they are not the holder of the data themselves.