Is duolingo actually dangerous?

Related questions

1. What is going on with duolingo?
2. How long does it take to become fluent in Japanese?
3. Can you ever finish duolingo?
4. Is duolingo good?
5. How good is duolingo?
6. Can I learn Korean on duolingo?
7. How effective is duolingo in learning a language?
8. Which is better duolingo or Memrise?
9. Does duolingo have a desktop app?
10. What company owns duolingo?

Tags

1. #worry
2. #language
3. #perfectly
4. #learning
5. #popular
6. #internet
7. #reminders
8. #duolingo
9. #sites
10. #quite
11. #practice
12. #think
13. #email