Former Employer Possibly Suing

I am speaking to my lawyer tomorrow. It’s Sunday so just want to get some opinions. Details have been changed.

I worked for a consulting company for 8 years in Nagoya, and I quit last year to start my own business doing something similar, but not the same.

Clients from the former company approached me and asked for my services. I never encouraged them to quit, and even stated they could and should continue to use my former employer, but also could use me, too.

Former employer found out, and I have received a letter in the mail from their lawyer, stating:

1) I am stealing their clients

2) I am to tell them how much I have made from their clients (and pay them that amount)

3) I am to immediately stop servicing these clients

Now, the letter is full of conjecture that I laughed at, some of the things they are accusing me of are just pure fabrications (they said, for example, I have a man that touts for their clients that visits the area around the office – yet I am the sole employee of my business and have never returned to their office)

There is no date on response, it just basically says “stop doing this and show us how much you made”

I laughed at this letter because there is no proof and it almost seems like they forced their lawyer to write it. It’s not even on professional paper, looks janky as hell.

Am I right in thinking that this is just a scare tactic? I don’t even want to reply but I will consult my lawyer tomorrow and ask. Any and all opinions are welcome.