Question

I’d like to remove on google maps placed on my website the Google Adv (on the right-bottom of each map) :

Map Data 2011 Google PPWK ...

is it possible?

Answer 1

See http://www.google.com/permissions/geoguidelines.html

Edit: (copy content from comment)
The relevant piece of the linked page is as follows, in case the page becomes unavailable:

FAQ #1:

Can you give me permission to show your content without
attribution, or put the attribution at the end of my book/movie/TV
show?

Without exception, we require attribution when Content
is shown. If you are unwilling to meet our attribution requirements,
please contact our data provider(s) directly to inquire about
purchasing the rights to the content directly.