In 1791 Symonds was charged with seditious libel and imprisoned in Newgate prison for publishing the second half of Thomas Paine's 'The Rights of Man', becoming one of the 'Newgate radicals'.

[1] He was buried on 4 May 1816 in St Mary's church Beddington, Surrey,[2] According to Manogue, James Ridgway succeeded to Symonds' business after his death in 1816,[3] but this may refer to some of his copyrights.

[11] In an attempt at reducing his sentence, Symonds had previously written to the Attorney-General on 22 February 1793, 'the extensiveness and nature of my business... in which I circulate more books than any man in England, has pointed me out to designing men as their dupe...

[14] The imprisonment of Symonds, Ridgway and other 'Newgate radicals' was twice recorded by the engraver Richard Newton in 1793 in an etching titled “Promenade in the State Side of Newgate” (1793) and a coloured acquatint entitled 'Soulagement en prison'.

[15] Whilst in prison Symonds jointly published William Winterbotham's four volume, An historical, geographical, commercial, and philosophical view of the American United States, (1795) together with imprisoned booksellers John Ridgway and Daniel Holt.

A reference dated 15 April 1806, when Symonds joined 'The friends of literature' described him as a retired bookseller, although his name continued to appear on new imprints until 1808.