Nevertheless, these issues are not new to medicine and should not come as a surprise to anyone.
Some European countries enforce an all-out ban on all SPAM like communication or require prior-consent.
However, non-commercial actors like researchers are often accepted from such regulations.
However, most users will never complete the survey.
In one experiment we found that while 3,000 of 20,000 accessed the website directly with their phone, only 500 completed the survey.