I remember writing a website for one office (tourism) So, did not pay. Naturally, all the logins and passwords remained with us, customers did not even dare to change them (although in this case the hole was left).

After 2 weeks, after the agreed payment period, I go to the hosting, quickly knock the page with the inscription "The site is temporarily blocked due to non-payment to developers" And in 10 seconds there is a redirect to the site of their competitors: )

Over half an hour has passed since I received an SMS to fill the bill. A penny in a penny was in line with the agreed amount.

Changed all back Customers didn’t even call.)