Jacob Appelbaum, a security researcher, Tor developer, and volunteer with Wikileaks, reported today on his Twitter feed that he was detained, searched, and questioned by US Customs and Border Patrol agents during preclearance on January 19, returning to the US from Toronto, Canada. The incident took place in Canada, with US agents.

If this post sounds familiar to you as a regular reader of Boing Boing, that is because it is the third such incident Appelbaum has been subjected to at the hands of federal agents: first, in mid-2010 at Newark airport, then the same thing yet again just this month in Seattle. On both January 2011 trips, he did not carry any electronics with him in anticipation of repeated detention, search, and interrogation.

Appelbaum is not accused of any crime. This is what being on a secret government watchlist looks like.

An archive of his tweeted account from today follows, beginning with this post.

• I made it home to Seattle and was detained yet again. This time on the Canada side and it was quite strange.



• This CBP encounter was different as nearly everyone involved was quite friendly all of the time. No good cop or bad cop games

• I was detained for around twenty minutes in total this time and very lightly searched. They didn't want to image my USB disk this time.



• They put me in an interrogation room with a large window. Ironically, it had a view of a computer screen with my file on it.

• This time there was no forensics person waiting – the people questioning me claimed this was just a secondary search for prohibited items.

• I think it's quite amusing that while they claimed it was merely for fruits and vegetables, they were making calls, searching the net, etc.

• CBP edits and reads your file while simultaneously using Internet Explorer to search the web while you're detained. That seems cybersecure!

• The Toronto, Canada pre-customs clearance CBP detainment was nicer than Seattle. Everything is still an improvement on my Newark experience.

• I was happy to see that because of pre-clearance, Canada is treated as a domestic flight and so I had no ICE handler at my arrival gate.



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When I requested to see my file, the CBP agent denied my request. He said something like: "People would know someone is looking for them…"



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I pointed out my obvious detention in a CBP interrogation room. He agreed that his reasoning did not apply as they already had me.

• This is political harassment without question.

• The main reason that these detentions are getting shorter is because I have learned how to streamline their searches at great personal cost.

• I'm looking forward to a time when I'm not on a secret watch, search, harass, detain, interrogate, delay, annoy and stress list.