We designed Browshot and Thumbalizr to be very easy to try out. You can create a free account and try some screenshots without verifying your e-mail address. You can even make a screenshot without registering at all. We had some abuses in the past but they did not impact the service. Since free users and paying customers use different browsers, they affected only other free users who had to wait longer for their screenshot to finish. But recently, we had to deal with a different type of abuse.

Cryptocurrencies are all the rage these days. Many of them offer users to gain free coins by doing heavy computation for them, typically to validate transactions. It is now possible to do the computation in the browser through many Javascript libraries. These Javascript mining libraries have been used in several websites, pushed by the publisher to make money off their visitors, or through malicious advertising. In the past few weeks, hundreds of fake account were created on Browshot and Thumbalizr and an excessive number of demos were requested. All of them pointed to different pages running cryptocurrency mining. Because of the very high CPU resources used by these sites, this impacted all browsers running on the same server.

We have disabled the fake accounts and strengthen our registration process and demos to avoid further abuses. We did this without making it harder for legitimate users to test out Browshot or Thumbalizr.