<s>
PeerGuardian	B-Application
is	O
a	O
free	B-License
and	I-License
open	I-License
source	I-License
program	O
developed	O
by	O
Phoenix	O
Labs	O
(	O
software	O
)	O
.	O
</s>
<s>
It	O
is	O
capable	O
of	O
blocking	O
incoming	O
and	O
outgoing	O
connections	O
based	O
on	O
IP	B-Protocol
blacklists	O
.	O
</s>
<s>
The	O
aim	O
of	O
its	O
use	O
was	O
to	O
block	O
peers	O
on	O
the	O
same	O
torrent	O
download	O
from	O
any	O
visibility	O
of	O
your	O
own	O
peer	O
connection	O
using	O
IP	B-Protocol
lists	O
.	O
</s>
<s>
The	O
Windows	O
version	O
of	O
this	O
program	O
has	O
been	O
discontinued	O
in	O
favor	O
of	O
other	O
applications	O
(	O
Phoenix	O
Labs	O
encourage	O
current	O
PeerGuardian	B-Application
users	O
to	O
migrate	O
to	O
PeerBlock	B-Application
which	O
is	O
based	O
on	O
PeerGuardian	B-Application
2	I-Application
)	O
.	O
</s>
<s>
Development	O
on	O
PeerGuardian	B-Application
started	O
in	O
late	O
2002	O
,	O
led	O
by	O
programmer	O
Tim	O
Leonard	O
.	O
</s>
<s>
The	O
original	O
PeerGuardian	B-Application
(	O
1.0	O
)	O
was	O
programmed	O
in	O
Visual	B-Language
Basic	I-Language
and	O
quickly	O
became	O
popular	O
among	O
P2P	O
users	O
despite	O
blocking	O
only	O
the	O
common	O
TCP	O
protocol	O
and	O
being	O
known	O
for	O
high	O
RAM	O
and	O
CPU	O
usage	O
when	O
connected	O
to	O
P2P	O
networks	O
.	O
</s>
<s>
Due	O
to	O
Version	O
1.0	O
only	O
blocking	O
TCP	O
ports	O
PeerGuardian.net	O
then	O
shifted	O
to	O
bluetack.co.uk	O
where	O
Protowall	O
,	O
The	O
blocklist	O
Manager	O
,	O
B.I.M.S	O
and	O
the	O
Hosts	O
Manager	O
were	O
developed	O
.	O
</s>
<s>
After	O
7	O
months	O
of	O
development	O
,	O
in	O
February	O
2005	O
Version	O
2	O
of	O
PeerGuardian	B-Application
was	O
released	O
as	O
a	O
beta	O
.	O
</s>
<s>
Speed	O
and	O
resource	O
inefficiencies	O
were	O
fixed	O
by	O
re-designing	O
and	O
re-coding	O
Version	O
2.0	O
in	O
C++	B-Language
to	O
consume	O
less	O
processing	O
power	O
and	O
memory	O
.	O
</s>
<s>
As	O
with	O
most	O
other	O
desktop	O
firewall	B-Application
software	I-Application
for	O
Windows	O
,	O
Version	O
2.0	O
is	O
installed	O
as	O
a	O
kernel-level	O
filter	O
in	O
Windows	O
2000	O
and	O
later	O
,	O
giving	O
the	O
application	O
direct	O
access	O
to	O
the	O
Windows	O
networking	O
stack	O
and	O
improving	O
performance	O
.	O
</s>
<s>
Support	O
for	O
both	O
Windows	B-Application
Vista	I-Application
and	O
IPv6	B-Protocol
were	O
in	O
release	O
candidate	O
phase	O
as	O
of	O
May	O
2009	O
.	O
</s>
<s>
The	O
binary	O
formats	O
(	O
known	O
as	O
P2B	O
)	O
were	O
created	O
at	O
the	O
release	O
of	O
the	O
first	O
beta	O
version	O
of	O
PeerGuardian	B-Application
2	I-Application
,	O
in	O
order	O
to	O
create	O
the	O
smallest	O
possible	O
blocklist	O
.	O
</s>
<s>
P2B	O
Version	O
1	O
–	O
This	O
format	O
was	O
used	O
only	O
in	O
the	O
earliest	O
releases	O
of	O
PeerGuardian	B-Application
2	I-Application
.	O
</s>
<s>
It	O
was	O
compressed	O
using	O
the	O
gzip	B-Application
format	O
.	O
</s>
<s>
P2B	O
Version	O
2	O
–	O
The	O
most	O
widely	O
used	O
format	O
,	O
this	O
is	O
supported	O
among	O
a	O
number	O
of	O
applications	O
,	O
including	O
eMule	B-Protocol
and	O
the	O
Linux	B-Application
version	O
of	O
PeerGuardian	B-Application
.	O
</s>
<s>
P2B	O
Version	O
3	O
–	O
The	O
newest	O
version	O
of	O
the	O
P2B	O
format	O
,	O
this	O
is	O
currently	O
supported	O
only	O
on	O
the	O
latest	O
version	O
of	O
the	O
Windows	O
version	O
of	O
PeerGuardian	B-Application
2	I-Application
.	O
</s>
<s>
The	O
original	O
format	O
for	O
PeerGuardian	B-Application
version	O
1.x	O
was	O
a	O
simple	O
plaintext	O
format	O
.	O
</s>
<s>
This	O
format	O
also	O
is	O
used	O
in	O
eMule	B-Protocol
,	O
in	O
the	O
SafePeer	O
Vuze	B-Application
plugin	O
,	O
ProtoWall	O
,	O
KTorrent	B-Language
,	O
and	O
Transmission	B-Language
.	O
</s>
<s>
Since	O
at	O
least	O
2006	O
,	O
the	O
P2P	O
blocklist	O
used	O
by	O
PeerGuardian	B-Application
has	O
been	O
provided	O
by	O
"	O
Bluetack	O
Internet	O
Security	O
Solutions	O
"	O
.	O
</s>
<s>
(	O
"	O
Bluetack	O
"	O
was	O
the	O
name	O
of	O
the	O
member	O
of	O
the	O
original	O
PeerGuardian	B-Application
team	O
who	O
owned	O
its	O
previous	O
domain	O
peerguardian.net	O
and	O
created	O
the	O
"	O
Block	O
List	O
Manager	O
"	O
used	O
to	O
maintain	O
the	O
list	O
.	O
)	O
</s>
<s>
Bluetack.co.uk	O
developed	O
an	O
application	O
called	O
the	O
Bluetack	O
Internet	O
Management	O
System	O
(	O
B.I.M.S	O
)	O
that	O
would	O
spider	O
whois	O
servers	O
to	O
create	O
a	O
map	O
of	O
the	O
internet	O
and	O
all	O
of	O
its	O
IP	B-Protocol
Addresses	I-Protocol
.	O
</s>
<s>
With	O
this	O
database	O
the	O
admins	O
of	O
the	O
site	O
(	O
Seraphielx	O
,	O
Moore	O
,	O
Firstaid	O
,	O
Tozanno	O
,	O
DeathAngel	O
,	O
R00ted	O
)	O
would	O
search	O
for	O
names	O
of	O
Anti-P2P	O
companies	O
and	O
set	O
a	O
status	O
code	O
in	O
the	O
entry	O
to	O
make	O
the	O
blocklists	O
that	O
would	O
be	O
downloaded	O
by	O
the	O
blocklist	O
manager	O
for	O
import	O
into	O
PeerGuardian	B-Application
,	O
Protowall	O
,	O
and	O
other	O
applications	O
that	O
would	O
block	O
Anti-P2P	O
traffic	O
from	O
accessing	O
your	O
download	O
.	O
</s>
<s>
The	O
PeerGuardian	B-Application
developers	O
state	O
they	O
have	O
no	O
control	O
over	O
Bluetack	O
's	O
list	O
,	O
and	O
do	O
not	O
promote	O
or	O
link	O
to	O
alternative	O
lists	O
.	O
</s>
<s>
PeerGuardian	B-Application
acknowledges	O
that	O
Battlefield	O
2	O
,	O
Blizzard	O
,	O
Steam	B-Application
,	O
and	O
ArenaNet	O
connectivity	O
is	O
blocked	O
,	O
which	O
creates	O
problems	O
for	O
many	O
online	O
gaming	O
users	O
who	O
are	O
not	O
aware	O
that	O
PeerGuardian	B-Application
will	O
break	O
game	O
connectivity	O
,	O
and	O
are	O
thus	O
directed	O
to	O
read	O
the	O
manual	O
.	O
</s>
<s>
With	O
the	O
blocklist	O
manager	O
application	O
,	O
users	O
can	O
add	O
these	O
sites	O
to	O
a	O
"	O
Safe	O
list	O
"	O
allowing	O
them	O
to	O
continue	O
using	O
the	O
Games	O
and	O
websites	O
without	O
interference	O
from	O
PeerGuardian	B-Application
.	O
</s>
<s>
In	O
2007	O
,	O
Bluetack/PeerGuardian	O
2	O
were	O
criticized	O
for	O
blocking	O
denis.stalker.h3q.com,	O
the	O
second	O
largest	O
BitTorrent	B-Protocol
tracker	I-Protocol
as	O
of	O
December	O
2007	O
,	O
as	O
an	O
"	O
Anti-P2P	O
"	O
address	O
,	O
and	O
claiming	O
that	O
its	O
maintainers	O
(	O
whose	O
tracking	O
software	O
"	O
Opentracker	B-Language
"	O
is	O
also	O
used	O
by	O
The	B-Application
Pirate	I-Application
Bay	I-Application
)	O
were	O
conspiring	O
with	O
the	O
MPAA	O
and	O
MediaDefender	O
.	O
</s>
<s>
The	O
maintainers	O
are	O
members	O
of	O
the	O
Chaos	O
Computer	O
Club	O
(	O
CCC	O
)	O
,	O
a	O
long-standing	O
association	O
of	O
hackers	O
and	O
freedom	O
of	O
information	O
activists	O
,	O
and	O
had	O
also	O
briefly	O
run	O
their	O
tracker	B-Protocol
from	O
the	O
CCC	O
's	O
own	O
network	O
.	O
</s>
<s>
Although	O
IP	B-Protocol
addresses	I-Protocol
of	O
government	O
and	O
business	O
entities	O
are	O
easily	O
added	O
to	O
a	O
list	O
of	O
IP	B-Protocol
addresses	I-Protocol
to	O
be	O
blocked	O
,	O
there	O
is	O
no	O
means	O
for	O
PeerGuardian	B-Application
to	O
block	O
access	O
by	O
a	O
government	O
or	O
business	O
using	O
an	O
undocumented	O
IP	B-Protocol
address	I-Protocol
to	O
identify	O
people	O
engaged	O
in	O
copyright	O
infringement	O
or	O
other	O
possibly	O
unlawful	O
activity	O
.	O
</s>
<s>
PeerGuardian	B-Application
Lite	O
is	O
a	O
derivative	O
of	O
PeerGuardian	B-Application
2	I-Application
made	O
to	O
consume	O
as	O
little	O
CPU	O
and	O
RAM	O
as	O
possible	O
.	O
</s>
<s>
It	O
is	O
also	O
open-source	B-Application
,	O
allowing	O
for	O
future	O
derivatives	O
by	O
any	O
party	O
.	O
</s>
<s>
As	O
its	O
developers	O
reported	O
online	O
,	O
Peerguardian	B-Application
Lite	O
is	O
now	O
continued	O
under	O
the	O
project	O
and	O
program	O
Peerblock	B-Application
,	O
and	O
Peerguardian	B-Application
Lite	O
users	O
were	O
recommended	O
from	O
around	O
2008	O
on	O
to	O
switch	O
to	O
Peerblock	B-Application
.	O
</s>
<s>
Peerblock	B-Application
has	O
some	O
more	O
options	O
,	O
but	O
uses	O
almost	O
as	O
little	O
CPU	O
as	O
Peerguardian	B-Application
Lite	O
did	O
.	O
</s>
<s>
Besides	O
the	O
original	O
criticism	O
of	O
Version	O
1	O
being	O
slow	O
and	O
buggy	O
,	O
most	O
other	O
criticism	O
of	O
PeerGuardian	B-Application
is	O
around	O
the	O
actual	O
technique	O
used	O
to	O
block	O
peers	O
.	O
</s>
<s>
Critics	O
have	O
pointed	O
out	O
that	O
the	O
blocklists	O
are	O
open	O
to	O
the	O
public	O
,	O
and	O
thus	O
parties	O
who	O
may	O
wish	O
to	O
circumvent	O
PeerGuardian	B-Application
can	O
actively	O
check	O
the	O
list	O
to	O
see	O
if	O
their	O
IP	B-Protocol
addresses	I-Protocol
have	O
been	O
blocked	O
.	O
</s>
<s>
The	O
blocklists	O
are	O
also	O
managed	O
by	O
the	O
public	O
,	O
but	O
there	O
is	O
no	O
fool-proof	O
method	O
on	O
checking	O
or	O
reporting	O
why	O
an	O
IP	B-Protocol
address	I-Protocol
or	O
range	O
are	O
bad	O
,	O
nor	O
on	O
checking	O
if	O
the	O
blocked	O
IP	B-Protocol
addresses	I-Protocol
still	O
remain	O
bad	O
.	O
</s>
<s>
Vista	B-Application
64	O
bit	O
and	O
Windows	O
7	O
64	O
bit	O
are	O
listed	O
for	O
application	O
compatibility	O
,	O
but	O
require	O
a	O
work	O
around	O
involving	O
disabling	O
driver	O
signing	O
that	O
may	O
require	O
some	O
degree	O
of	O
computer	O
skill	O
.	O
</s>
