spam on S Anand

Phone Rage and an OTP Flood

Tue, 29 Apr 2025 10:25:30 +0000

I called a few movers in Chennai, including “Unicorn Packers & Movers”, listed at 7015580411.

He couldn’t understand what I said. I said, “We’re shifting to a house in Mylapore,” and he asked, “Shifting house where in Hyderabad?” (The reason became clear later.)

It seemed I had the wrong number, so I said, “No, sorry, we need someone else,” and hung up.

His phone rage began. He called back and said, “Why did you wake me up and waste my time?” From his tone it was clear I couldn’t say anything helpful. From the quality of my signal it was clear I couldn’t have a meaningful conversation. So I just put the phone down without cutting it.

He called me again. I answered and left the phone on the table.

That’s when the phone rage began. He called me 5 times from 9467186002 and twice from 7015580411. I answered and left the phone on the table.

Then the SMS flood hit. Between 2:47 pm and 2:55 pm, he sent me 40 OTPs:

6 from KukuFM: An Indian audio app for podcasts, audiobooks, and short lessons.
5 from Hyundai: A global car maker that sells vehicles in India.
4 from Zepto: A rapid-delivery startup for groceries and essentials.
4 from ZestMoney: A finance app that lets you buy now and pay in EMI, no credit card needed.
3 from Samsung Shop: Samsung’s online store for browsing and buying its electronics.
3 from Confirmtkt: An online service for booking train tickets via IRCTC.
3 from My11Circle: A fantasy-cricket game where you build virtual teams and win cash prizes.
3 from Aakash Institute: A coaching center for medical and engineering entrance exams.
2 from JioCinema: Jio’s OTT service with movies, shows, and originals.
2 from NetMeds: An online pharmacy for medicines and health products.
2 from AJIO: A fashion and lifestyle e-commerce site by Reliance Retail.
2 from Jar: A savings app that rounds up your spend and saves the extra.
1 from RummyCircle: An online rummy card game.

After a break, he tried again at 3:17 pm with less energy:

1 from ZestMoney
1 from Samsung Shop

To me, it was instructive. I learnt about KukuFM, Jar, Ajio, My11Circle and many others. I also know which services to annoy people with OTPs. If you want to prank-spam OTPs, here’s your hit list!

My apologies to the man I awoke – hope he gets some sleep. And thanks for teaching me something new!

PS: The featured image was generated using the prompt: Edit this image so that this photo of me looks at a smartphone as a surreal storm of OTP notifications rains down around me.

Here’s ChatGPT’s version of that. Yes, that’s vaguely like me.

Bayes’ Theorem

Mon, 11 Oct 2010 14:53:01 +0000

I’ve tried understanding Bayes’ Theorem several times. I’ve always managed to get confused. Specifically, I’ve always wondered why it’s better than simply using the average estimate from the past. So here’s a little attempt to jog my memory the next time I forget.

Q: A coin shows 5 heads when tossed 10 times. What’s the probability of a heads?
A: It’s not 0.5. That’s the most likely estimate. The probability distribution is actually:

That’s because you don’t really know the probability with which the coin will throw a heads. It could be any number p. So lets say we have a probability distribution for it, f(p).

Initially, you don’t know what this probability distribution is. So assume they’re all the same – a flat function: f(p) = 1

Now, given this, let’s say a heads falls on the next toss. What’s the revised probability distribution? It’s:

f(p) ← f(p) * probability(heads | x) / probability(heads) = 1 * (x^1 * (1-x)^0) / 1 = x

Let’s say the next is again a heads. Now it’s

f(p) ← f(p) * probability(heads | x) / probability(heads) = x * (x^1 * (1-x)^0) / 1 = x^2

Now if it’s a tails, it becomes:

f(p) ← f(p) * prob(tails | x) / prob(tails) = x^2 * (x^0 * (1-x)^1) / 1 = x^2 * (1-x)

… and so on. (This happens to be a called a Beta distribution.)

Now, instead of this being the probability of heads, it could be the probability of a person having blood pressure, or a document being spam. As you get more data, the probability distribution of the probability keeps getting revised.

Comments

Ram 18 Jan 2012 1:59 pm: Hi Anand, f(p) ← f(p) * probability(heads | x) / probability(heads) = 1 * (x^1 * (1-x)^0) / 1 = x What I understand from the above notation is f(p) stands for probability distribution function (which is used recursively), x stands for the probability of getting a head (which is unknown) and 1-x stands for the complement of x. Can you please explain why the distribution function is defined as you have done? i.e. , f(p) ← f(p) * probability(heads | x) / probability(heads)

Paypal spam

Mon, 12 Jun 2006 12:00:00 +0000

I almost fell for this piece of spam.

Spam techniques

Sun, 20 Mar 2005 12:00:00 +0000

Spammer ploys. From the Scientific American.

Smarter spam

Sat, 18 Jan 2003 12:00:00 +0000

Smarter spam via Scripting News

Spam is a virus

Sat, 26 Oct 2002 12:00:00 +0000

The thin line between spam and virus. In the form of a “Friend Greeting”. via Metafilter

Anders talked to a spammer

Sat, 07 Sep 2002 12:00:00 +0000

andersja talked to a spammer. Some insights into the spamming world.

Different approach to spam

Wed, 21 Aug 2002 12:00:00 +0000

A different approach to spam. Habeas is using haikus to morph spam into copyright violation – making it more prosecutable. Clever, but practical?

Charge for eliminating spam

Tue, 30 Jul 2002 12:00:00 +0000

Here’s a good business model. Buy a free e-mail provider. Add spam. Then charge for eliminating spam. Good thing I got rid of my Hotmail account.

Do not reply to spam

Fri, 07 Sep 2001 12:00:00 +0000

A warning from Yahoo not to reply to spam saying “Remove me from the mailing list”.

Anil hates forwards

Tue, 28 Aug 2001 12:00:00 +0000

Anil hates forwards too.

You can sue spammers

Wed, 02 May 2001 12:00:00 +0000

Ellen won a spam case against Kozmo. If you get unsolicited e-mail from a company, you can sue them. Unless they have an opt-out mechanism.