We see this trend as well, but in our case we have a lot of control over the client's IP. since we're generally a hosting company, when someone doesn't pay and doesn't tell us why (we send out payment reminders, then SMS, and phone-calls), then we simply cut-off their websites
Some see it as cruel, but it's effective. If you want to stay in business and have your website up and running, then the least you can do is to pay your hosting bill as well. It's only fair to pay your debtors when you expect your client's to pay you
But, with physical labor (i.e. web development, or network installations) this is somewhat of a different ball-game. Even with a 50% upfront deposit we still get clients who don't pay the final bill and simply disappear afterwards
Did you like this article? Share it with your favourite social network.