This is a feature suggestion – primarily for the API, but it could also be built purely in any client by filtering outputs of existing API capabilities.

Description: On each user profile page, where you currently have the tabs (or dropdown options) Overview, Comments, Posts, create a filtering option to only show those entries that contain an URL.

How this helps combat advertising spam: Putting links in comments (especially through later edits) is an established tactic of Reddit spammers. Whenever we get a feeling that some account seems spammy, but we don’t want to spend inordinate amounts of time sifting through their comments, viewing only those comments that have links in them would be a powerful tool to estimate whether it’s worth to dig further and possibly report that account. (Keep in mind that a big part of Mastodon’s resilience against spammers seems to be based on the active rejection of spam by its community.)

Privacy considerations: This feature would merely shorten the time it takes to see what link-containing comments someone has posted; the information itself is already out there for everyone to see and crawl. Besides, the URLs that people post don’t usually reveal much more about them than their writings, and if someone does wants to stalk somebody, they’ll go through everything anyway. An exception would be links that accidentally share more than what was intended, but such exceptions will remain a needle in a haystack. On the other hand, anything that reduces spam links will enhance our privacy, as we’ll less often be misled to click on worthless spying websites. Nonetheless, I’m open to hear if anyone sees bigger concerns with this proposal.