I recently started gathering information about poker and poker online. I had no idea about it and I have spent about a week surfing the web (mainly using Google) and consulting different web pages and forums.

Today, I received a phone call offering me some kind of special price in an online casino which I obviously don't want. They have told me they have obtained my cell phone because I have been surfing the looking for information about poker.

I have not been able to obtain any more information. I am somewhat worried about how they got my telephone number and what's more important, about how they know I have recently started to search for poker online and all that.

I can summarize my internet privacy like this:

  • I have no Facebook acount, nor Twitter, nor any other kind of social network.
  • I have a Gmail account which indeed has my phone number.
  • I also have an Amazon account which also has my phone number associated with it.
  • During the process of searching for information about poker I registered myself in a forum, but I didn't gave them any kind of private information, not even my name (I used a different email account that I use for these kinds of things )
  • I also bought in Amazon an e-book about poker, and the Seller was Amazon EU Sarl.
  • I have also performed a virus scan and my updated AV software hasn't found any problem.
  • 1
    Phone numbers aren't really big secrets if someone knows your name. You can find number on the web through a pretty simple search. There's a whole marketplace for trading peoples search activity, complete with automated auctions. Commented Feb 25, 2016 at 21:33
  • My guess would be your ISP (or some network eavesdropper) has your phone number (or name from which they can look up your phone number) and has observed you browsing for poker books on amazon (which by default does not use HTTPS when browsing for content), and sold your interest to a third party advertiser. Granted this isn't any sort of proof and is probably fundamentally unknowable who sold it from the limited information given. I doubt Amazon or Google would directly sell your phone number and poker interest to a casino to make phone calls.
    – dr jimbob
    Commented Feb 25, 2016 at 21:34
  • @dr jimbob I can probably provide more information if you ask what you need.
    – MNLR
    Commented Feb 25, 2016 at 21:36
  • Probably a supercookie placed by your mobile provider sherbit.io/how-does-verizons-supercookie-work
    – munkeyoto
    Commented Feb 25, 2016 at 21:41
  • @D1X - My point is you don't know who sold it or the complete set of potential actors who are aware you like poker and can figure out your phone number. Without set of potential leakers being just 1 or the third-part advertiser telling you who gave them your phone number, we can't figure this out conclusively. That said browsing a website in HTTP let's any network eavesdropper between you and the website see your IP and your poker interest. Any website you've used your real name at (or your ISP) can tell your IP address matches your name and can probably get your phone number.
    – dr jimbob
    Commented Feb 25, 2016 at 21:52

2 Answers 2


As mentioned by multiple people that commented, there are many ways that this could have happened, and any guess as to how this happened is largely based on conjecture.

Having said that, my guess is that one of the sites that you visited may have used some sort of marketing automation tool (such as Marketo), which (possibly through the use of browser fingerprinting or 3rd-party cookies) identified you, and got your phone number by cross-referencing you with some other database.

At http://launchpoint.marketo.com/netfactor/782-visitortrack/, Marketo advertises that they can "...turn invisible web visitors into actionable prospect intelligence including Company name, Address, Phone number, Website, key Executives, email addresses and more".

  • 8
    That is completely disgusting Commented Feb 26, 2016 at 18:20
  • browser fingerprinting is exactly why the 'do not track' header was/is a bad idea: the extra entropy provided results in better trackability.
    – Jacco
    Commented Mar 18, 2016 at 9:17

That is very unethical, what happened to you. This is why we need stricter privacy laws like the EU has. Google or Amazon do not sell or provide access to your phone number to third parties (if you read their privacy policies), unless of course there is a court order which is unlikely in your case. So it wasn't through them. When you visited poker sites, it may be that a third-party advertising network which had already placed cookies on your device matched that interest in poker with your personal information gathered from perhaps another website visit where you actually did provide, say, an email address? Then, using public databases shared by information brokers (again, an industry which has raised significant privacy concerns but remains unregulated) it was able to match that interest to a phone number.

Or, it could be your ISP selling this information. Depends on what country you are from though. I would be very surprised if you are in the European Union and an EU ISP was using your browsing history to target advertising - I don't think that's legally justifiable in the EU (whereas it is legal in the USA). So if you are in the EU, you might consider contacting your national data protection agency (in the UK, this is the Information Commissioner's Office (ICO)). But if you are outside the EU, it may well have been your ISP doing this. Check their privacy policy and terms and conditions that come with your contract with them. You should be able to find out if they are using browsing history for targeting advertising.

Also, in relation to a previous answer about the Marketo product, it states on their website that this is primarily for B2B tracking purposes, i.e. for business-to-business transactions. For example, if a computer manufacturing company is checking out an electronics components company's website, Marketo will let the latter know the details of the computer manufacturing company so that better marketing can take place. Since many corporate networks have a static IP address when connecting to the open internet, this kind of information gathering by Marketo is actually a lot easier compared to gathering contact information for individual people. Because individual people, browsing the internet from home, don't often have a static IP as their ISP is most likely to use DHCP, meaning their IP address can vary - meaning Marketo's job would be slightly harder. Still a privacy concern, but just thought to clarify the purpose of the product outlined in that link in a previous answer by mti2935.

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