Ole hyvä ja kirjaudu sisään! Jos et ole vielä rekisteröitynyt, sekin onnistuu ohessa.
Browser: Firefox 50.1.0
Engine: Greasemonkey 3.9
OS: Linux (Arch)
First of all, thanks for this! I had a quick crack at a counter-measure, but gave up when I realised it would require actual effort :-)
Just noticed that it causes the duration drop-downs (e.g. "Last 30 days") on the user's home page  to not be displayed and makes them unresponsive on library pages . (Actually, I noticed the latter was broken a while back, but only just figured out it's caused by this.)
Also, disabling the userscript, it looks like last.fm have removed this annoyance (for now at least).