<s>
A	O
spambot	B-Protocol
is	O
a	O
computer	B-Application
program	I-Application
designed	O
to	O
assist	O
in	O
the	O
sending	O
of	O
spam	O
.	O
</s>
<s>
Spambots	B-Protocol
usually	O
create	O
accounts	O
and	O
send	O
spam	O
messages	O
with	O
them	O
.	O
</s>
<s>
Email	O
spambots	B-Protocol
harvest	O
email	O
addresses	O
from	O
material	O
found	O
on	O
the	O
Internet	O
in	O
order	O
to	O
build	O
mailing	O
lists	O
for	O
sending	O
unsolicited	O
email	O
,	O
also	O
known	O
as	O
spam	O
.	O
</s>
<s>
Such	O
spambots	B-Protocol
are	O
web	B-Application
crawlers	I-Application
that	O
can	O
gather	O
email	O
addresses	O
from	O
websites	O
,	O
newsgroups	O
,	O
special-interest	O
group	O
(	O
SIG	O
)	O
postings	O
,	O
and	O
chat-room	O
conversations	O
.	O
</s>
<s>
Because	O
email	O
addresses	O
have	O
a	O
distinctive	O
format	O
,	O
such	O
spambots	B-Protocol
are	O
easy	O
to	O
code	O
.	O
</s>
<s>
A	O
number	O
of	O
programs	O
and	O
approaches	O
have	O
been	O
devised	O
to	O
foil	O
spambots	B-Protocol
.	O
</s>
<s>
One	O
such	O
technique	O
is	O
address	O
munging	O
,	O
in	O
which	O
an	O
email	O
address	O
is	O
deliberately	O
modified	O
so	O
that	O
a	O
human	O
reader	O
(	O
and/or	O
human-controlled	O
web	B-Application
browser	I-Application
)	O
can	O
interpret	O
it	O
but	O
spambots	B-Protocol
cannot	O
.	O
</s>
<s>
This	O
has	O
led	O
to	O
the	O
evolution	O
of	O
more	O
sophisticated	O
spambots	B-Protocol
that	O
are	O
able	O
to	O
recover	O
email	O
addresses	O
from	O
character	O
strings	O
that	O
appear	O
to	O
be	O
munged	O
,	O
or	O
instead	O
can	O
render	O
the	O
text	O
into	O
a	O
web	B-Application
browser	I-Application
and	O
then	O
scrape	O
it	O
for	O
email	O
addresses	O
.	O
</s>
<s>
Alternative	O
transparent	O
techniques	O
include	O
displaying	O
all	O
or	O
part	O
of	O
the	O
email	O
address	O
on	O
a	O
web	O
page	O
as	O
an	O
image	O
,	O
a	O
text	O
logo	O
shrunken	O
to	O
normal	O
size	O
using	O
inline	O
CSS	B-Language
,	O
or	O
as	O
text	O
with	O
the	O
order	O
of	O
characters	O
jumbled	O
,	O
placed	O
into	O
readable	O
order	O
at	O
display	O
time	O
using	O
CSS	B-Language
.	O
</s>
<s>
Forum	O
spambots	B-Protocol
browse	O
the	O
internet	O
,	O
looking	O
for	O
guestbooks	O
,	O
wikis	B-Protocol
,	O
blogs	O
,	O
forums	B-Application
,	O
and	O
other	O
types	O
of	O
web	B-General_Concept
forms	I-General_Concept
that	O
they	O
can	O
then	O
use	O
to	O
submit	O
bogus	O
content	O
.	O
</s>
<s>
These	O
often	O
use	O
OCR	B-Application
technology	O
to	O
bypass	O
CAPTCHAs	O
.	O
</s>
<s>
One	O
way	O
to	O
prevent	O
spambots	B-Protocol
from	O
creating	O
automated	O
posts	O
is	O
to	O
require	O
the	O
poster	O
to	O
confirm	O
their	O
intention	O
to	O
post	O
via	O
email	O
.	O
</s>
<s>
Since	O
most	O
spambot	B-Protocol
scripts	O
use	O
a	O
fake	O
email	O
address	O
when	O
posting	O
,	O
any	O
email	O
confirmation	O
request	O
is	O
unlikely	O
to	O
be	O
successfully	O
routed	O
to	O
them	O
.	O
</s>
<s>
Some	O
spambots	B-Protocol
will	O
pass	O
this	O
step	O
by	O
providing	O
a	O
valid	O
email	O
address	O
and	O
use	O
it	O
for	O
validation	O
,	O
mostly	O
via	O
webmail	B-Protocol
services	O
.	O
</s>
<s>
Using	O
methods	O
such	O
as	O
security	O
questions	O
are	O
also	O
proven	O
to	O
be	O
effective	O
in	O
curbing	O
posts	O
generated	O
by	O
spambots	B-Protocol
,	O
as	O
they	O
are	O
usually	O
unable	O
to	O
answer	O
it	O
upon	O
registering	O
,	O
also	O
on	O
various	O
forums	B-Application
,	O
consistent	O
uploading	O
of	O
spam	O
will	O
also	O
gain	O
the	O
person	O
the	O
title	O
'	O
spambot	B-Protocol
 '	O
.	O
</s>
<s>
A	O
Twitterbot	O
is	O
a	O
program	O
used	O
to	O
produce	O
automated	O
posts	O
on	O
the	O
Twitter	B-Application
microblogging	O
service	O
,	O
or	O
to	O
automatically	O
follow	O
Twitter	B-Application
users	O
.	O
</s>
<s>
Others	O
post	O
@replies	B-Application
or	O
automatically	O
"	O
retweet	O
"	O
in	O
response	O
to	O
tweets	O
that	O
include	O
a	O
certain	O
word	O
or	O
phrase	O
.	O
</s>
<s>
Some	O
Twitter	B-Application
users	O
even	O
program	O
Twitterbots	O
to	O
assist	O
themselves	O
with	O
scheduling	O
or	O
reminders	O
.	O
</s>
