The group claims the 'BP logo represents a stain on Tate's  international reputation'If you thought BP put all UK to sleep with its “Yanks want our pensioners poor” propaganda, you are wrong.

I noted this Tate Gallery  protest in the LA paper today: tar and feathers were appropriately brought to the exhibit BP proudly sponsors

and then I searched further and found this

Oil painting: Artists gatecrash Tate Britain’s summer party in protest at BP sponsorship

It has photos like this one
Protest: A woman pours oil and feathers outside the entrance to  the Tate Britain in central London, which is hosting the Tate Britain  summer

Love the group’s name: The Good Crude Britannia. I found the  FB site for them if you are interested