'Random spot checks' happen, but worse.
If you are single mum the benefits agency keep tabs. After my husband 1st left (Tory govt) I was summoned to an interview after about 6 months- extremely nosey, personal and told that they put ppl like me under surveillance to catch them out!
Unknown to me my ex still had one of his credit cards registered at what was our house (mail diverted). Because of this they presumed he was living with me, I had to send in 6 months of bank statements, wage slips, bills etc and when they didn't receive it due to their shit mail system stopped everything!
Got it sorted but anyone who thinks it's easy is on a different planet.
Likewise ESA. I went on it following a massive breakdown and hospitalisation. Was on the 'assessment' phase for 10 months- which is now the new rate and not enough to live on. I had to keep sending in sick notes which entailed either sending them in and having payments delayed/stopped because of their shit post system. Or the phone line advise you to go to your local job centre plus to get it in immediately, and every time I did that I was belittled and one time shouted and ranted at in the open plan office, for having the cheek to do what the phone line told me to!
I'm trying to remain stable, and working towards getting back to work by the way before I get scrounge bandied about 