I'm back on Twitter.

I can imagine the cries of "I knew he wouldn't last!" from the Twitterati.

But give me a few minutes of your time and I'll tell you why I'm back and the real truth about exactly why I left in the first place.

In my blog of 12 August entitled Walking, Not Running, I talked about my time on Twitter and my basic reasons for leaving. I stand over a lot of what I said. The atmosphere there has changed and there have been negative stories in the media about trolling, etc, for months now. The brand has been damaged and Twitter needs to act fairly swiftly to repair it. At the time of writing that blog, for reasons that will become obvious, I was very sketchy about my own personal experience.

When I left Twitter numerous people thought it was as a result of an overreaction on my behalf. That my departure was a kneejerk reaction to a couple of "trolling" or "flaming" incidents or that I was attention seeking. The reality of the situation is that my wife and I were targeted for over three years.

It started in July 2009. I'd been on Twitter for over two years at that point, having joined in May 2007, and I'd never had a problem. My account was followed by a fairly innocuous looking one which I followed back and within 10 minutes I had received a direct message (DM) calling me a "Dirty fucking Jewish scumbag". I blocked the account and reported it as spam. The following week it happened again in an identical manner. A new follower, I followed back, received a string of abusive DMs, blocked and reported for spam. Two or three times a week. Sometimes two or three times a day. An almost daily cycle of blocking and reporting and intense verbal abuse. So I made my account private and the problem went away for a short while. There were no problems on Twitter but my Facebook account was hacked, my blog was spammed and my email address was flooded with foulmouthed and disgusting comments and images. Images of corpses and concentration camps and dismembered bodies.

Again, it eased off for a couple of weeks. I relaxed. Thought they'd finally tired of failing to get a reaction from me. Boy, was I wrong.

I didn't mention it to my wife. Didn't see the point of worrying her. But then she joined Twitter to see what it was like and grew to enjoy it. It wouldn't have been immediately obvious to outsiders that we were man and wife. She made the mistake, though, of changing her profile to state that she was "The long suffering wife of @LeoTraynor". Not a good idea. She received a DM stating: "Your husband is scum. A rotten bastard and you're a whore." She laughed it off. Blocked and reported and then the pattern started again. We got to the point of not accepting new followers at all and then one day my wife received a torrent of abuse via DM and on the timeline that was so vile she's never been on Twitter since – which is a real shame as she has so much to share and is far more interesting than I am.

People kept asking me, "Why you? Why would these guys want to have a go at you?" I couldn't answer them other than it was a couple of random idiots who didn't appreciate my political views or ethnic origins. Or even someone who couldn't solve my cryptic crosswords!

The whole thing escalated in June, July and August this year. I received more and more abuse on the timeline and via DMs. A crossword clue account I'd started (@Leo'sClue) was inundated with abuse too.

Then one day something happened that truly frightened me. I don't scare easily but this was vile.

I received a parcel at my home address. Nothing unusual there – I get lots of post. I ripped it open and there was a Tupperware lunchbox inside full of ashes. There was a note included, saying, "Say hello to your relatives from Auschwitz". I was physically sick.

I was petrified. They had my address. I reported it to the authorities and hoped for the best.

Two days later I opened my front door and there was a bunch of dead flowers with my wife's old Twitter username on it. Then that night I received a DM. "You'll get home some day & ur bitches throat will be cut & ur son will be gone."

I got on to the authorities again but, polite and sympathetic as they were, there didn't seem much that could be done.

Every night for weeks I lost sleep over it. Listening for noises. Opening the door everyday with trepidation. Trying to maintain a semblance of normality and not let my wife or son see that I was dying on the inside. Mortified that they might be in danger because of my big mouth or ancestry.

Then the last straw. I received another tweet, on the public timeline this time. "I hope you die screaming but not until you see me piss on ur wife."

I closed my account immediately and swore I'd never go back, in spite of the friends I have there.

I made it clear that I would pursue the troll or trolls and that I would take action. What I didn't say though was that I'd already been pursuing them for weeks and had a very good idea where, if not who, they were.

In July I was approached by a friend who's basically an IT genius, and he offered some help. He said that he could trace the hackers and trolls for me using perfectly legal technology, which would lead to their IP addresses. I said yes. Then I baited them – I was deliberately more provocative toward them than ever I'd been before.

Holidays intervened. My Twitter account was deactivated but before doing so I posted links to my Google+ account, blog and invited people to contact me on Facebook. I'm delighted that a lot of my lovely friends did. I'm also delighted that The Troll did too.

It transpired that the abuse had emanated from three separate IP addresses in different corners of Ireland. Two of them were public wifi locations but the third … The third location was the interesting one.

The third location was a friend's house.

The Troll was his son. His 17-year-old son.

I was gobsmacked.

I spoke to my friend at length. He told me how his son was always glued to his laptop, tablet or smartphone. How he couldn't watch a TV show without tweeting about it simultaneously. About how he'd become engrossed in conspiracy sites. It also became clear that the other two IP addresses had been used by his son.

He was horrified at what his son had done. Horrified, but not surprised. He wanted to call the authorities there and then and turn him in. But I said no.

A couple of days after that conversation I met my friend, his wife and their son in a quiet and discreet location. The son, The Troll who'd almost driven me mad, was totally unaware that I'd be joining them.

I sat down and ordered a big pot of tea. "Do you still like choc chip cookies?" I asked The Troll and he nodded eagerly, a shadow of the little boy that was flickering across his face.

We had a chat. I told them about my wife and son. I told them about my recent illnesses and bereavements and about the builders having been in. I asked after their business and asked The Troll how college is going. All bright and breezy and a trip down memory lane. Then The Troll's dad tipped me the wink and I opened my bag and took out my manila folder.

I showed The Troll's mother and father screengrabs and printouts of his handiwork.

I showed them pictures of ashes and dead flowers.

I pointed out that one of the messages my wife received wishing me dead had arrived when I actually was gravely ill.

I told them of how I'd become so paranoid that I genuinely didn't know who to trust anymore.

I told them of nights when I'd walked the rooms, jumping at shadows and crying over the sleeping forms of my family for fear that they would suffer because of me.

Then it happened …

The Troll burst into tears. His dad gently restraining him from leaving the table.

I put my hand on his shoulder and asked him: "Why?"

The Troll sat there for a moment and said "I don't know. I don't know. I'm sorry. It was like a game thing."

A game thing.

So, that's what it was …

The Troll's mother said: "If you want to call the garda we'll support you in that. I'm ashamed of him."

I responded: "I'm not criminalising a 17-year-old kid and ruining his future. But I will write about it – and you must all guarantee me that he'll go and see a counsellor about this or I will go legal on you."

Then I got up to leave. I looked The Troll in the eye and said: "Stand up."

He stood. I said: "Look at me. I'm a middle-aged man with a limp and a wheeze and a son and a wife that I love. I'm not just a little avatar of an eye. You're better than this. You have a name of your own. Be proud of it. Don't hide it again and I won't ruin it if you play ball with your parents. Now shake hands."

"I'm sorry," he said, and looked like he meant it. "Thanks for giving me a break dude."

Then we shook on it.

And that is how I came to shake the hand of a troll.

• This article originally appeared on traynorseye.com and is republished with permission. The author has asked us to make clear he does not want to be paid a fee