Is it againts the TOS? How to do it?

AdSense unit with no 'Ads by Google' footer, I am sure it is against the TOS, because the AdSense Code is totally change, I saw it on abona.com site, it's parked on sedoparking.

Is it OK for me to do the same thing?

 

No it's not OK, you're not allowed to change the code.

SEDO (and other parking services) don't display the same type of AdSense ads, but they have specials arrangements with Google, so it's not against the TOS for them.

 

It is not worth getting banned over. If you try and change any part of the code you will be banned.

 

So, for me it sound unfair, Google always said will treat small business sites the same as they treat big sites.

 

Yes, Monty is right. In addition, Premium Members of AdSense also get different Ads format from Google.

 

Of course it's not OK.
You will get banned if you do something like this.

 

it's against for you. sedo is a premium publisher. when you become a premium publisher, you can hide it too. you need 20.000.000 page view to become a prmimum publisher