Who is Facebook's mysterious "Lan Tim 2"?

by @edent | # # # | 13 comments | Read ~94,992 times.

Facebook has an interesting feature. It will let you see which companies have associated your off-Facebook activity with your Facebook account. If you visit:
https://www.facebook.com/off_facebook_activity/
you'll see what companies are snitching on you to Facebook.

Off-Facebook activity includes information that businesses and organisations share with us about your interactions with them. Interactions are things such as visiting their website or logging in to their app with Facebook.

Because I use the Firefox web browser, all my off-FB activity is kept private from Facebook. I don't use FB to sign into things. I also run an ad-blocker. So I expected my "Off Facebook Activity" to be completely blank.

It wasn't.

Facebook activity page saying they received data from "Lan Tim 2".

Who are Lan Tim 2? And what did I purchase from them? First up, let's check that I'm as paranoid as I think I am...

Blank apps and websites page.

Yup! I've connected nothing to my FB account.

Perhaps I'm being a dolt. Perhaps I signed in to a store with Facebook without thinking about it? Perhaps it is a legitimate purchase.... And then I saw this:

I don't know Christopher - although we appear to have some mutual friends. It strikes me as a bit odd that two random individuals, who are both pretty privacy conscious, would both have made the same mistake which led to a Facebook associated purchase.

I checked through all my credit card statements and emails. I didn't purchase anything around that time, and I couldn't find any reference to the merchant.

You can download your Facebook data as JSON. So I did that. This is all it had about those mystery transactions:

Scrap of JSON which doesn't say much.

What's going on?

It's actually a bit more complicated than that

Off-Facebook activity doesn't just mean stuff that happens online. Facebook also does offline conversions which allows advertisers to match offline activity with online activity..

we use a process called matching to match the hashed information with Facebook profiles so that you can advertise to your customers on Facebook, Instagram and Audience Network. The more information you can provide, the better the match rate

Suppose I go to a restaurant, and I booked using my name and phone number. The restaurant sends that data to Facebook to say "Terence Eden ate at this restaurant on this day." Facebook can then tell if I saw an advert which led me to make a purchase.

A good reason to use a disposable phone number for everything!

I reached out to a friend who worked at Facebook. Obviously they couldn't tell me too much, but here's what I did find out.

Lan Tim 2 supply custom printed apparel. Print your logo on a t-shirt or mug, that sort of thing. They're a "white label" operation. That is, you buy from "Tom's Terrific T-Shirts" but it's Lan Tim 2 who print and supply the final item.

Had I bought anything like that? I didn't think so. And then, I remembered...

Spreadshirt! I'd made some custom printed t-shirts through them. I contacted a few other people who'd seen Lan Tim 2. They'd also used Spreadshirt! And, like me, their last purchase was inconsistent with the data given to Facebook.

I assume I gave my phone number to Spreadshirt to provide delivery information.

If this is correct, then it looks to me like Spreadshirt took the phone numbers given to it for one reason - and then used them for another.

Or, perhaps I'm wrong, and some dodgy company has been randomly spamming Facebook with fake data?

It goes to show, Facebook's level of transparency of data isn't good enough.

13 thoughts on “Who is Facebook's mysterious "Lan Tim 2"?

  1. Amarketer says:

    It's just offline conversion events being uploaded so you'd stop getting these ads, or so they can market to you again in the future. You purchased this product, gave them a phone number.. Not sure where the issue lies? You agreed to the terms on Spreadshirt which is probably where you opted for marketing.

  2. Jill says:

    "It goes to show, Facebook's level of transparency of data isn't good enough." - I would say it goes to show, Facebook's ability to collect data even from their most private users.

  3. John Doe says:

    Lookup a company called FullContact.

    Emails/phone numbers get SHA256 hashed, and compared to their graph db via an API.

    How they’ve assembled that DB, I don’t know, but they have amassed a huge collection of data.

    Companies work with clients to match their customer data to this data, so they can use the social networks to profile customers and advertise to them.

    1. JD says:

      I would assume FullContact pulled their DB from all the business card scans people did on their system. I believe they used to offer a service to automate the task of reading business cards.

      1. Yakubu Jalal says:

        That is correct. They had such a service last time I looked ( which was around 2013).

      2. DPC says:

        They post mechanical Turk tasks to transcribe business card details. Or used to anyway. I suspect they moved to a more AI/ML solution and less on manual translations as their tasks don't appear too often.

        Data enrichment is a big business in general.

  4. No Thanks says:

    Of more concern to me, a non Facebook user (I use 0 social media) is that they collect this data anyway. See Zuck's testimony to Congress.

  5. Adam Jacob Muller says:

    I have LAN TIM 2 on my facebook account and I have never bought anything from spreadshirt.

    Moreover my facebook account is just a dummy one which only has the bare minimum of information to own my business page, which I don't even post to (I have dedicated social media people who do that).

    Facebook doesn't even have my phone number, only my name and my business email address.

    Very creepy.

    1. Brian says:

      Did you visit another page while logged in to that Facebook account. Most interactions can be recorded through "business-tools" association while surfing other pages. Make sure you only open fb in-private mode. Do not open anything else inside the same session. Close it down.

  6. Mayson Lancaster says:

    Anybody know who or what DiepTrinh is? Facebook has me purchasing from them 4 times in 3 days in November ’19, and I have no purchases on the one card I use on those days… Weird!

    1. Jude Gibbons says:

      If you Google DiepTrinh you get a Hacker News post where someone is complaining that they had the same names (DiepTrinh and lan tim) appear in the same way on 5 March 2020.

    2. Greg (UK) says:

      Same here. I track me expenses, no purchases made on those days at all, yet DiepTrinh shows up

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