This happens in Europe, too. In Finland, in several towns it is not unusual for (the most nondiscriminating) public restrooms to be used for heroin injection, with the needle then disposed of in the toilet bowl, preventing the next visitor from using it and making the cleaner's job even more unpleasant. I am sure this has happened in Germany at least at some points in history when some cities were internationally infamous for heroin.
Cool story bro. Heroin use is practically nonexistent in Finland, opioid addicts use cheaper and easier to obtain alternatives.