This has happened on this very wiki! (Not repeatedly, though): after TV Tropes was mentioned in xkcd, a mob of newbies washed over the forums and wiki, trashing the servers.
Through the nature of Wiki Walking, TV Tropes itself has a tendency to give support to YouTube videos that illustrate a certain trope. These videos would otherwise probably fall into YouTube obscurity, and thus you may see a top comment saying "Who else got here from TV Tropes?"
Dummied Out: Using the "view source" button on some pages here will reveal commented-out lines in the wiki markup (lines which begin with %% are comments). At times, these may include examples that were hidden because they didn't meet the Wiki standards, but weren't completely removed in hopes that some troper, someday, would save them.
It's become harder and harder to find archives of some of the old Troper Tales as time has gone on. Some tales were never archived at all.
Due to The Great Crash, some portions of the site are lost, at least on TV Tropes itself; whether archive sites like the Wayback Machine saved copies is not guaranteed.
Newbie Boom: This wiki gets a Newbie Boom each time an outside community links in. xkcd linked here once and killed the server for part of a day.
Old Shame: Many longtime tropers are ashamed of the former Troper Tales and Fetish Fuel sections of the site, and for good reason. The entries there were so... uh, off-color, giving wayToo Much Information about the tropers who posted there, that they damn near dragged this site's reputation down to the level of 4chan. Thankfully, it was removed and will never come back. The two sections were moved to separate sites, which are now both offline.
Vaporware: The 2.0 update has been touted for years as a significant overhaul of the wiki, particularly in terms of how convenient editing and maintenance would be with it. Since it was announced, there have been more minor updates instead, such as 2018's 1.8 update.