I did read the article. The article
and the legal thinking are badly
confused and, really, nonsense.

Why? The main reason why and
my point in my post is that blocking the IP address
is just silly talk since an IP address can't
be used at all reliably to identify a
computer or user. The IP address is
nearly irrelevant.

The Web site might as well find that the
person, say, Tom, they didn't like
ate at McDonald's and then try to block
everyone who eats at McDonald's. Then
Tom can eat at Wendy's, and everyone
who does continue to eat at McDonald's
gets blocked and maybe accused of violating
the C&D letter. Again, once again,
over again, yet again, IP address just
says next to nothing about who
did or did not connect to the Web site.
So, IP address should be ignored in
this legal discussion.

Away from McDonald's and more specifically
about the Internet,
(1) The user who got
the C&D letter could just use a different
IP address. One way to do that is to us
a proxy as in the article. Another way
is just to disconnect the electrical power
from a cable modem and connect power
again. Then the modem will likely forget the
IP address it was last assigned, use
the internet standard dynamic host
connection protocol (DHCP) to get another
IP address from the Internet service
provider (ISP), and continue on. Another
way is, the ISP can just assign a
different IP address at any time for
any reason. So, the person, Tom, who received
the C&D letter can get a new IP address
and, indeed, be forced to give up his old
IP address. And the user, Tom, need not
even be aware of this change in IP address.

(2) The Web site could get torqued
at the wrong person. So, the ISP
of the person receiving the C&D letter, Tom,
could assign the the IP address
blocked by the Web site to another
person, Joe, not involved in any of
the legal efforts, and Tom could try to connect
to the Web site. Then the Web site could
blame Tom for access to their site by Joe.
Bummer for Joe.

For your

> just see if 3taps has data from the craigslist website that was after the effective date of the IP block

that's not nearly "easy enough". Even to start to
look for this data, need full access to at least
the computer of the person who got the C&D letter,
Tom.

So, have to grab Tom's computer. By what right?
Tom can claim that he has been honoring the C&D letter and
not been accessing the
Web site and that the blocked IP address has
been assigned to someone else, Joe.

Even if get Tom's computer, now what? He could
have several trillion bytes of data on his computer,
and also have other computers in his house/office.
Looking for the Craigslist data could be a lot
of work and very intrusive, whether Tom
had the data or not. The search could
uncover business plans, love letters,
etc. Tom should be able to keep private.

The Craigslist data could be anywhere in that data
or nowhere. The data could be encrypted. Tom
might have copied the data to DVD and hidden it
in the bottom of his kitty cat's litter box,
under insulation in his attic, in one of
several hundred books on his bookshelf, etc.
Pawing through all of Tom's private
possessions all based in IP address or less
is outrageously intrusive and wildly unfair to Tom.

Next, it need not be the least bit clear
in what form the data is. The data, as
sent by Craigslist, is essentially just
simple text plus maybe some pictures in
JPG, GIF, PNG, etc. A lot of that text
data is HTTP, HTML, and CSS tokens,
symbols, and markup that has next to
nothing to do with the Craigslist data
at issue;
those tokens, etc. can easily be
removed by a simple program or text
editor leaving just the data.
That data can be pulled into
a spreadsheet, written to a database
(e.g., SQL Server or MySql),
combined with other data in
files, tables, etc., graphed,
formatted with TeX, PostScript,
PDF, etc., and look nothing much
like a Web page from Craigslist.
So, turning Tom's house upside down
promises to uncover nothing relevant
to the C&D letter.

Since maybe Tom is honoring the C&D letter,
turning his house upside down
is not justified by any evidence and
is unfair to Tom.

Moreover, maybe Tom got the Craigslist
data from, say, a Google archived
copy or a friend or another Web site.

"Easy enough" is a very long way from
being true: It's easy for Tom
to have what looks like Craigslist
data when he did honor the C&D letter.
It's easy for Tom not to have honored
the C&D letter and have some Craigslist
data but be next to impossible to
know this, no matter what devastation
is inflicted on Tom's house or office.

More generally, the Web site is volunteering
to send its data over the Internet to
computers and software that request the
data via a HTTP GET request. About all
the Web site knows is that there was
a GET request from an IP address;
neither the GET request nor the IP
address say anything meaningful
about a person. It's not the least
bit clear who the person is.
That's just how the
Internet works. If the Web site doesn't
like that, then they can shut down.

So, really, the Web site can send all
the letters they want, but they have
no evidence that should justify
searching what data Tom has or if
Tom did or did not honor the C&D letter.

The Web site effectively put the data
out there in the public square
for everyone, anonymously,
to see, copy, keep, and in
some, and maybe all, respects use. Then later
the Web site changed their mind and
wants some absurd restrictions based
on some nearly meaningless evidence.
The data is offered to anonymous users,
and it is not clear just who the users
are, and no amount of C&D letter
writing and IP address tracking, etc.
can change that.