1) Ohh you worked you for xyz company, do you know Mr. ABC ? etc etc. => ou think the agent is genuine and trushtworthy and tend to give more information as he asks. You end up no emails/calls further.
2) I need 2 references from your old employers, this is mandatory as part of our screening blah blah. Like a humble guy I passed those details => they called my old/current employers and played double game... Mr.abcd in your department is looking for a job. I can fill his position with a lovely candidate.... he wants commission for placing and replacing me

3) You are CV is wonderful and one of my prestigous clients liked it.....I can get you a good hike with .. a,b,c,d benefits. But I need to know to which all companies you applied, agency names,managers you interviewed with etc..... ==> My CV/reputation got corrupted due to this
4) One lady talks sweetly (well as always)... asking too many personal things, r u married, have kids etc..........=> I think that they want to gauge responsibilities we have,,, so that we can spend more/less hours at new work place..
There are toooo many bunch of rogue agents who just fish the CV's. Later on with all the experience I speak / reveal information to guys only who ask 3 things straight away.
1) availability
2) rate
3) suitability with the role.
I might be wrong, but i find large recruitment firms are a bit better than small fishers. I always insists on email and never ever, give reference details before interview.
DONT GET EMOTIONAL &DONT GIVE REFERENCES BEFORE INTERVIEWS...
If you are bound to get a job you will, for sure. Have patience learn tips and tricks. Reciprocate according to agent's behavior. It's a rotten industry.Don't hesitate and dont reveal personal information.
Also try not to reply / apply to posts which asks tooooooooooo many skillsets which is virtually impossible for a single person. There are agents who will copy contents of your CV on to someone's. End of the day you look FAKE to employers.
IF POSSIBLE RELY SOLELY ON FRIENDS WHO CAN REFER YOU TO THERE CURRENT EMPLOYERS/AGENTS.THAT'S THE BEST IN UK AND IT WORKS LIKE A CHARM.