It's a bit confusing, but if I've understood right, Squire Patton Boggs have not themselves been raided. They were renting out space in their office suite to Cohen (which people on that Twitter thread say is common for legal firms), and it's only Cohen's space which has been raided.
However, no one can pretend it was just an office let, because of the following from September 2017:
Squire Patton Boggs announced a “strategic alliance” with Cohen back in April, with Cohen helping the firm land new clients and working out of Squire Patton Boggs’ offices in New York, Washington and London.
www.politico.com/tipsheets/politico-influence/2017/09/15/former-trump-lawyer-still-working-with-squire-patton-boggs-222315
That's Squire Patton Boggs who are also lobbyists for Gazprom, BTW.