RE: This may be bad, or may be good29 Jan 2020 08:52
Cambridge Analytica was a completely different beast in that it 'stole' data from facebook users, and in turn used that data to build profiles on individuals that they could then target and influence during election campaigns/referendums. This was known as weapons grade communications and required prior government approval.
Avast are simply selling anonymised data sourced via browsing habits. It also informed users their information could be collected, and gave them a chance to opt out.
The share price fall is most definitely a reaction based on the reputational damage of a few tech site articles, combined with broker downgrades and coronavirus threat.