<s>
Social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
,	O
also	O
peer-to-peer	O
social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
,	O
is	O
an	O
area	O
of	O
computer	O
science	O
that	O
generalizes	O
cloud	B-Architecture
computing	I-Architecture
to	O
include	O
the	O
sharing	O
,	O
bartering	O
and	O
renting	O
of	O
computing	O
resources	O
across	O
peers	O
whose	O
owners	O
and	O
operators	O
are	O
verified	O
through	O
a	O
social	O
network	O
or	O
reputation	O
system	O
.	O
</s>
<s>
It	O
expands	O
cloud	B-Architecture
computing	I-Architecture
past	O
the	O
confines	O
of	O
formal	O
commercial	O
data	O
centers	O
operated	O
by	O
cloud	O
providers	O
to	O
include	O
anyone	O
interested	O
in	O
participating	O
within	O
the	O
cloud	B-Architecture
services	I-Architecture
sharing	O
economy	O
.	O
</s>
<s>
Peer-to-peer	O
(	O
P2P	O
)	O
computing	O
and	O
networking	O
to	O
enable	O
decentralized	O
cloud	B-Architecture
computing	I-Architecture
has	O
been	O
an	O
area	O
of	O
research	O
for	O
sometime	O
.	O
</s>
<s>
Social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
intersects	O
peer-to-peer	O
cloud	B-Architecture
computing	I-Architecture
with	O
social	O
computing	O
to	O
verify	O
peer	O
and	O
peer	O
owner	O
reputation	O
thus	O
providing	O
security	O
and	O
quality	O
of	O
service	O
assurances	O
to	O
users	O
.	O
</s>
<s>
Social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
has	O
been	O
highlighted	O
as	O
a	O
potential	O
benefit	O
to	O
large-scale	O
computing	O
,	O
video	O
gaming	O
,	O
and	O
media	O
streaming	O
.	O
</s>
<s>
The	O
tenets	O
of	O
social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
has	O
been	O
most	O
famously	O
employed	O
in	O
the	O
Berkeley	B-Operating_System
Open	I-Operating_System
Infrastructure	I-Operating_System
for	I-Operating_System
Network	I-Operating_System
Computing	I-Operating_System
(	O
BOINC	B-Operating_System
)	O
,	O
making	O
the	O
service	O
the	O
largest	O
computing	O
grid	O
in	O
the	O
world	O
.	O
</s>
<s>
Another	O
service	O
that	O
uses	O
social	B-General_Concept
cloud	I-General_Concept
computing	I-General_Concept
is	O
Subutai	O
.	O
</s>
<s>
In	O
the	O
case	O
of	O
traditional	O
cloud	B-Architecture
computing	I-Architecture
,	O
availability	O
on	O
demand	O
is	O
essential	O
for	O
many	O
cloud	O
customers	O
.	O
</s>
<s>
Social	B-General_Concept
Cloud	I-General_Concept
Computing	I-General_Concept
does	O
n't	O
provide	O
this	O
availability	O
guarantee	O
because	O
in	O
a	O
P2P	O
environment	O
,	O
peers	O
are	O
mobile	O
devices	O
which	O
may	O
enter	O
or	O
leave	O
the	O
P2P	O
network	O
at	O
any	O
time	O
,	O
or	O
PCs	O
which	O
have	O
a	O
primary	O
purpose	O
that	O
can	O
override	O
the	O
P2P	O
computation	O
at	O
any	O
time	O
.	O
</s>
