Harm or damage is not limited to things you can count as monetary loss. It can also be sleepless nights, feeling anxious or frightented, having personal data leaked that might or might not be used to harm you later.
dailymail.co.uk/news/article-2…
helpnetsecurity.com/2015/01/26/pol…
Same code, mostly, but one is malware and one is clean. proofpoint.com/us/threat-insi…
1. We simply don't know the intent in most cases.
2. Your "good intent" still doesn't free you from your responsibility to not harm anyone.
en.wikipedia.org/wiki/Morris_wo…
gdatasoftware.com/blog/2016/11/2…
E.g., a screenlocker you can kill via task manager is still malware.
Non tech savyy users aren't able to do that.