<s>
AdBlock	B-Operating_System
is	O
an	O
ad-blocking	O
browser	B-Protocol
extension	I-Protocol
for	O
Google	B-Application
Chrome	I-Application
,	O
Apple	B-Application
Safari	I-Application
(	O
desktop	O
and	O
mobile	O
)	O
,	O
Firefox	B-Application
,	O
Opera	B-Application
,	O
and	O
Microsoft	B-Application
Edge	I-Application
.	O
</s>
<s>
AdBlock	B-Operating_System
allows	O
users	O
to	O
prevent	O
page	O
elements	O
,	O
such	O
as	O
advertisements	O
,	O
from	O
being	O
displayed	O
.	O
</s>
<s>
The	O
AdBlock	B-Operating_System
extension	O
was	O
created	O
on	O
December	O
8	O
,	O
2009	O
,	O
which	O
is	O
the	O
day	O
that	O
supports	O
for	O
extensions	O
was	O
added	O
to	O
Google	B-Application
Chrome	I-Application
.	O
</s>
<s>
AdBlock	B-Operating_System
's	O
efforts	O
are	O
not	O
related	O
to	O
Adblock	B-Application
Plus	I-Application
.	O
</s>
<s>
The	O
developer	O
of	O
AdBlock	B-Operating_System
,	O
Michael	B-Operating_System
Gundlach	I-Operating_System
,	O
claims	O
to	O
have	O
been	O
inspired	O
by	O
the	O
Adblock	B-Application
Plus	I-Application
extension	O
for	O
Firefox	B-Application
,	O
which	O
is	O
itself	O
based	O
on	O
the	O
original	O
Adblock	B-Operating_System
that	O
ceased	O
development	O
in	O
2004	O
.	O
</s>
<s>
Since	O
2016	O
,	O
AdBlock	B-Operating_System
has	O
been	O
based	O
on	O
the	O
Adblock	B-Application
Plus	I-Application
source	O
code	O
.	O
</s>
<s>
In	O
July	O
2018	O
,	O
AdBlock	B-Operating_System
acquired	O
uBlock	B-Protocol
,	O
a	O
commercial	O
ad-blocker	O
owned	O
by	O
uBlock	B-Protocol
LLC	O
and	O
based	O
on	O
uBlock	B-Protocol
Origin	I-Protocol
.	O
</s>
<s>
AdBlock	B-Operating_System
was	O
sold	O
to	O
an	O
anonymous	O
buyer	O
in	O
2015	O
and	O
on	O
October	O
15	O
,	O
2015	O
,	O
Gundlach	O
's	O
name	O
was	O
taken	O
down	O
from	O
the	O
site	O
.	O
</s>
<s>
In	O
the	O
terms	O
of	O
the	O
deal	O
,	O
the	O
original	O
developer	O
Michael	B-Operating_System
Gundlach	I-Operating_System
left	O
operations	O
to	O
Adblock	B-Operating_System
's	O
continuing	O
director	O
,	O
Gabriel	O
Cubbage	O
,	O
and	O
as	O
of	O
October	O
2	O
,	O
2015	O
,	O
AdBlock	B-Operating_System
began	O
participating	O
in	O
the	O
Acceptable	B-Application
Ads	I-Application
program	O
.	O
</s>
<s>
Acceptable	B-Application
Ads	I-Application
identifies	O
"	O
non-annoying	O
"	O
ads	O
,	O
which	O
AdBlock	B-Operating_System
shows	O
by	O
default	O
.	O
</s>
<s>
AdBlock	B-Operating_System
uses	O
the	O
same	O
filter	O
syntax	O
as	O
Adblock	B-Application
Plus	I-Application
for	O
Firefox	B-Application
and	O
natively	O
supports	O
Adblock	B-Application
Plus	I-Application
filter	O
subscriptions	O
.	O
</s>
<s>
Filter	O
subscriptions	O
can	O
be	O
added	O
from	O
a	O
list	O
of	O
recommendations	O
in	O
the	O
"	O
Filter	O
Lists	O
"	O
tab	O
of	O
the	O
AdBlock	B-Operating_System
options	O
page	O
,	O
or	O
by	O
clicking	O
on	O
an	O
Adblock	B-Application
Plus	I-Application
auto-subscribe	O
link	O
.	O
</s>
<s>
On	O
March	O
12	O
,	O
2016	O
,	O
in	O
support	O
of	O
World	O
Day	O
Against	O
Cyber	O
Censorship	O
,	O
and	O
in	O
partnership	O
with	O
Amnesty	O
International	O
,	O
instead	O
of	O
blocking	O
ads	O
,	O
AdBlock	B-Operating_System
replaced	O
ads	O
with	O
banners	O
linked	O
to	O
articles	O
on	O
Amnesty	O
's	O
website	O
,	O
written	O
by	O
prominent	O
free	O
speech	O
advocates	O
such	O
as	O
Edward	O
Snowden	O
,	O
to	O
raise	O
awareness	O
of	O
government-imposed	O
online	O
censorship	O
and	O
digital	O
privacy	O
issues	O
around	O
the	O
world	O
.	O
</s>
<s>
The	O
campaign	O
was	O
met	O
with	O
both	O
praise	O
and	O
criticism	O
,	O
with	O
AdBlock	B-Operating_System
's	O
CEO	O
,	O
Gabriel	O
Cubbage	O
,	O
defending	O
the	O
decision	O
in	O
an	O
essay	O
on	O
AdBlock	B-Operating_System
's	O
website	O
,	O
saying	O
"	O
We	O
’re	O
showing	O
you	O
Amnesty	O
banners	O
,	O
just	O
for	O
today	O
,	O
because	O
we	O
believe	O
users	O
should	O
be	O
part	O
of	O
the	O
conversation	O
about	O
online	O
privacy	O
.	O
</s>
<s>
Meanwhile	O
,	O
Simon	O
Sharwood	O
of	O
The	O
Register	O
characterized	O
Cubbage	O
's	O
position	O
as	O
"	O
 '	O
You	O
should	O
control	O
your	O
computer	O
except	O
when	O
we	O
feel	O
political	O
 '	O
,	O
says	O
AdBlock	B-Operating_System
CEO	O
"	O
.	O
</s>
<s>
On	O
September	O
13	O
,	O
2014	O
,	O
the	O
AdBlock	B-Operating_System
team	O
released	O
a	O
version	O
for	O
Firefox	B-Application
users	O
,	O
ported	O
from	O
the	O
code	O
for	O
Google	B-Application
Chrome	I-Application
,	O
released	O
under	O
the	O
same	O
free	B-Application
software	I-Application
license	O
as	O
the	O
original	O
Adblock	B-Operating_System
.	O
</s>
<s>
The	O
official	O
site	O
's	O
knowledge	O
base	O
article	O
on	O
December	O
7	O
,	O
2015	O
,	O
states	O
that	O
with	O
version	O
44	O
or	O
higher	O
of	O
Firefox	B-Application
desktop	O
and	O
Firefox	B-Application
Mobile	I-Application
,	O
AdBlock	B-Operating_System
will	O
not	O
be	O
supported	O
.	O
</s>
<s>
The	O
last	O
version	O
of	O
Adblock	B-Operating_System
for	O
those	O
platforms	O
will	O
work	O
on	O
older	O
versions	O
of	O
Firefox	B-Application
.	O
</s>
<s>
AdBlock	B-Operating_System
was	O
released	O
again	O
on	O
Mozilla	O
Add-ons	O
on	O
November	O
17	O
,	O
2016	O
.	O
</s>
<s>
On	O
April	O
1	O
,	O
2012	O
,	O
Adblock	B-Operating_System
developer	O
Michael	B-Operating_System
Gundlach	I-Operating_System
tweaked	O
the	O
code	O
to	O
display	O
LOLcats	O
instead	O
of	O
simply	O
blocking	O
ads	O
.	O
</s>
