Thanks @jkphl. It is very strange. I have had zero problems with @Foursquare/@SwarmApp for over 10+ years, and Dodgeball before that. As a private-only silo with no viral/amplification features, it’s stayed fairly calm & useful.
Dear @4sqSupport, apparently my @Foursquare/@SwarmApp account (https://foursquare.com/t) was erroneously deleted earlier today! :(
I sent email to support@ with only automated response.
Please undelete my account! Thanks! @t 
cc: @dens @zeldman