I am charged constantly 30 lindens for group liability

[examining]

As per https://community.secondlife.com/t5/Linden-Dollars-L/There-are-two-transactions-in-my-last-2-days-transaction-history/qaq-p/3001159
I am charged constantly 30 linden for group liability.
Also a transaction that I did not make (the 50 lindens #1407102988 transaction).

1) 2016-02-02 01:31:45 ad5613f9 Destination: Seagulls' friends
Group Liability L$30 L$20

2)2016-02-16 01:33:39 abfd86d4 Destination: Seagulls' friends
Group Liability L$30 L$-30

Today again same event.
A transaction I did not make took 30 linden and additionally group liability took another 30 and both left me with negative balance.

2016-02-23 02:58:41 6f58436f Destination: Commerce Linden
L$ Payment
Description: MKT2 Item Purchase Order #1409174180 L$0 L$-30
2016-02-23 01:33:02 7a996281 Destination: Seagulls' friends
Group Liability L$30 L$-30

Thought one pays an one time 100 fee for a group.
Is this alright? And should I file a support ticket again for the transactions I did not make? It's only 30+50 linden.
It's sure I did not make them as not only I had the impression both times that something magically stole my last pennies but I checked both times in my order history and there are no such transactions whatsoever in that date.

P.S.  Perhaps something rezzed in my sim takes that money, and I should find out since 30+50 it's no big deal but if that is going to hapen regularly it is.  As per the group liability I'd like to be informed really if I have to pay this or not and why is this happening.  For now I just top up my balance and go on.

P.S. 2 (After yr answers) . In about land I had indeed checked the show place in search. Is it enough to uncheck this or should I uncheck also the group to show in search? The question of the unknown transactions also, remains open.  Is there a way to identify transactions that do not show in history? Perhaps they are due to some object having been allowed to access my balance.  In such case can I find out which one from my account somewhere (not erasing one by one the suspects?)

Must I uncheck also the option for the group to be found in search too?

[Alwin Alcott]

it is your own group... of course you pay for that.

 

https://community.secondlife.com/t5/English-Knowledge-Base/Creating-managing-moderating-and-disbanding-groups/ta-p/700111

 

 

[Manwa Pastorelli]

Any group your a member of where you are set toPay Group Liabilities and Recieve Group Divedends. will bill your account for a percentage of those fees. The 30 lindens is a weekly  listing fee for a parcel. if you go to the groups profile, then to the Land & L$ tab you will be able to see which parcel is being billed for.

If this is your group and your parcel and you don't wish to list the parcel in search you can of course turn this off in about land. If the group is not yours you can request a roll which does not have pay liabilities option for you. If the group owner is not co-operative you can always leave the group.

Its worth knowing, that while that option is set, if the land is sold you will get a share of the sale price from that group owned land.